Reminder about your invitation from Anil Kumar Reddy Perugu

2011-06-06T06:41:00.001-07:00

This is a reminder that on May 29, Anil Kumar Reddy Perugu sent you an invitation to become part of his or her professional network at LinkedIn.

Follow this link to accept Anil Kumar Reddy Perugu's invitation.

https://www.linkedin.com/e/6vtq4n-golgz6yy-4q/doi/3036195000/WNiEJp2t/gir_630850096_1/EML-inv_17_rem/

Signing up is free and takes less than a minute.

On May 29, Anil Kumar Reddy Perugu wrote:

> To: [anilchinnu21.dotnet@blogger.com]
> From: Anil Kumar Reddy Perugu [anilchinnu21@gmail.com]
> Subject: Invitation to connect on LinkedIn

> I'd like to add you to my professional network on LinkedIn.
>
> - Anil Kumar Reddy

The only way to get access to Anil Kumar Reddy Perugu's professional network on LinkedIn is through the following link:

https://www.linkedin.com/e/6vtq4n-golgz6yy-4q/doi/3036195000/WNiEJp2t/gir_630850096_1/EML-inv_17_rem/

You can remove yourself from Anil Kumar Reddy Perugu's network at any time.

--------------

Reminder about your invitation from Anil Kumar Reddy Perugu

2011-05-31T04:59:00.001-07:00

This is a reminder that on May 29, Anil Kumar Reddy Perugu sent you an invitation to become part of his or her professional network at LinkedIn.

Follow this link to accept Anil Kumar Reddy Perugu's invitation.

https://www.linkedin.com/e/6vtq4n-gocso31e-39/doi/3036195000/WNiEJp2t/gir_630850096_0/EML-inv_17_rem/

Signing up is free and takes less than a minute.

The only way to get access to Anil Kumar Reddy Perugu's professional network on LinkedIn is through the following link:

https://www.linkedin.com/e/6vtq4n-gocso31e-39/doi/3036195000/WNiEJp2t/gir_630850096_0/EML-inv_17_rem/

You can remove yourself from Anil Kumar Reddy Perugu's network at any time.

--------------

Invitation to connect on LinkedIn

2011-05-29T01:15:00.001-07:00

I'd like to add you to my professional network on LinkedIn.

- Anil Kumar Reddy

Anil Kumar Reddy Perugu
Software Engineer at ValueLabs
Hyderabad Area, India

Confirm that you know Anil Kumar Reddy

How to and when to use ASP.NET IIS Registration Tool.

2008-11-19T21:44:00.000-08:00

If .NET framework is installed before IIS then we get this problem "Server application unavailable" when we run any application on IIS.

For this we need to register ASP.NET with IIS.

Go to command promt and go to .NET directory (C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727).
Then run this command aspnet_regiis -i for registering ASP.NET runtime with IIS. and aspnet_regiis -c for installing client side scripts.

The tool can also be used to determine which version of the common language runtime (CLR) is used for the application and also to display the status of all installed versions of ASP. NET, register the ASP.NET version that is coupled with the tool, create client-script directories, and perform other configuration operations.

Below are the options that we get with this tool.

Option	Description
-c	Installs the client-side scripts for ASP.NET, such as client-side validation scripts, to the aspnet_client subdirectory of each Internet Information Services (IIS) site directory. Only the client-side scripts for the ASP.NET version that is associated with Aspnet_regiis.exe are installed.
-disable	Disables ASP.NET in the IIS Security Console. This option can be combined only with the -i, -ir, or -r options. It is not available with IIS versions earlier than IIS 6.0.
-e	Removes the client-side scripts for ASP.NET from the aspnet_client subdirectory of each IIS site directory. Only the client-side scripts for the ASP.NET version associated with Aspnet_regiis.exe are removed.
-ea	Removes the client-side scripts for all versions of ASP.NET from the aspnet_client subdirectory of each IIS site directory.
-enable	Enables ASP.NET in the IIS Security Console. This option can be combined only with the -i, -ir, or -r options. It is not available with IIS versions earlier than IIS 6.0 or with ASP.NET versions earlier than ASP.NET version 2.0.
-ga user	Grants the specified user or group access to the IIS metabase and other directories that are used by ASP.NET. This option is not available with ASP.NET versions earlier than ASP.NET 2.0.
-i	Installs the version of ASP.NET that is associated with Aspnet_regiis.exe and updates the script maps at the IIS metabase root and below. Only the script maps for applications that use an earlier version of ASP.NET are updated. Applications that use a later version are not affected.
-ir	Installs the version of ASP.NET that is associated with Aspnet_regiis.exe and only registers ASP.NET in IIS. This option does not update the script maps. To install ASP.NET and update the script maps, use the -i option.
-k path	Removes the script maps to all versions of ASP.NET from all ASP.NET applications at the specified application root path and its subdirectories.
-kn path	Removes the script maps to all versions of ASP.NET from the ASP.NET application only at the specified application root path. This option does not affect applications in subdirectories of the specified path.
-lk	Lists the path and version of all IIS metabase keys where ASP.NET is mapped. The keys that inherit ASP.NET script maps from a parent key are not displayed.
-lv	Lists the status and installation path of all versions of ASP.NET that are installed on the computer.
-norestart	Inhibits the restart of the World Wide Web Publishing Service after installing or updating ASP.NET script maps. If you do not use this option, all application pools are recycled. Use this option with the -i or -r options when the IIS worker process will be restarted manually.
-r	Updates all of the script maps in the IIS metabase and below to point to the ASP.NET ISAPI version that is associated with Aspnet_regiis.exe. All existing script maps are updated to point to the ASP.NET ISAPI version that is associated with the ASP.NET IIS Registration tool, regardless of the current version.
-s path	Installs the script map that points to the ASP.NET ISAPI version associated with Aspnet_regiis.exe to all ASP.NET applications at the specified application root path and its subdirectories. All existing script maps in the specified path and below that use an earlier version of the ASP.NET ISAPI are updated.
-sn path	Installs the script map that points to the ASP.NET ISAPI version associated with the tool to the ASP.NET application at the specified application root path. All existing script maps in the specified path that use an earlier version of the ASP.NET ISAPI are updated. This option does not affect applications in subdirectories of path.
-u	Uninstalls the version of ASP.NET that is associated with the ASP.NET IIS Registration tool from the computer. Existing script maps to this version of the ASP.NET ISAPI are automatically remapped to the most recent remaining ASP.NET ISAPI version installed.
-ua	Uninstalls all versions of ASP.NET from the computer.
-?	Displays the command syntax and options for the ASP.NET IIS Registration tool.

Configuration Options

Option	Description
-config+	Enables remote access to ASP.NET configuration on the computer.
-config-	Disables remote access to ASP.NET configuration on the computer.
-pa container account	Grants permission for the specified user or group account to access the specified key container. This argument takes the following optional modifiers: -pku Substitutes a user-specified container for the default machine container. -csp provider Specifies the container provider to use. -full Specifies that full access should be added, rather than the default read-only access.
-pc container	Creates an RSA public/private key pair in the specified container. This argument takes the following optional modifiers: -size keySize Specifies the key size. The default is 1024 bytes. -pku Substitutes a user-specified container for the default key container on the computer. -exp Specifies that private keys must be able to be exported. -csp provider Specifies the container provider to use.
-pd section	Decrypts the configuration section. This argument takes the following optional parameters: -app virtualPath Specifies that decryption should occur at the level of the included path. -location subPath Specifies the subdirectory to decrypt. -pkm Specifies that the Machine.config file should be decrypted instead of the Web.config file.
-pdf section webApplicationDirectory	Decrypts the specified configuration section of the Web.config file in the specified physical (not virtual) directory.
-pe section	Encrypts the specified configuration section. This argument takes the following optional modifiers: -prov provider Specifies the encryption provider to use. -app virtualPath Specifies that encryption should occur at the level of the included path. -location subPath Specifies the subdirectory to encrypt. -pkm Specifies that the Machine.config file should be encrypted instead of the Web.config file.
-pef section webApplicationDirectory	Encrypts the specified configuration section of the Web.config file in the specified physical (not virtual) directory.
-pi container file	Imports an RSA public/private key pair to the specified container from the specified XML file. This argument takes the following optional modifiers: -pku Substitutes a user-specified container for the default machine container. -exp Specifies that private keys can be exported. -csp provider Specifies the container provider to use.
-pr container account	Removes permission for the specified user or group account to access the specified key container. This argument takes the following optional modifiers: -pku Substitutes a user-specified container for the default machine container. -csp provider Specifies the container provider to use.
-px container file	Exports an RSA public/private key pair from the specified container to the specified XML file. This argument takes the following optional modifiers: -pku Substitutes a user-specified container for the default machine container. -csp provider Specifies the container provider to use.
-pz container	Deletes the specified key container. This argument takes the following optional modifier: -pku Substitutes a user-specified container for the default machine container.

.Net Interview Questions, Resources, Tips & Tricks.: New features in C# 4.0

2008-11-15T23:19:00.000-08:00

New Features in C# 4.0 which will ship with Visual Studio 2010. Be first to Read and learn.

.Net Interview Questions, Resources, Tips & Tricks.: New features in C# 4.0

Cross Page Post Back Labels: ASP.NET 2.0

2008-07-24T07:08:00.000-07:00

ASP.Net 1.1 provides for web forms posting back only to themselves. In many situations, the solution requires posting to a different web page. The traditional workaround alternatives were to use Response.Redirect and/or Server.Transfer to move to a different page and simulate cross page post-back behavior.

ASP.Net 2.0 provides a feature known as Cross Page PostBack for a web form to post-back to a different web form (other than itself)

How to post to a different page

To set a web form to post back to a different web form, in the source web form, set the PostBackURL property of a control that implements IButtonControl (eg. Button, ImageButton, LinkButton) to the target web form. When the user clicks on this button control, the web form is cross-posted to the target web form. No other settings or code is required in the source web form.

Access source page info within the posted page: FindControl Method

The target web form resulting from the cross-page postback provides a non-null PreviousPage property. This property represents the source page and provides reference to the source web form and its controls.

The controls on the source page can be accessed via the FindControl method on the object returned by the PreviousPage property of the target page.

protected void Page_Load(object sender, EventArgs e)

{

...

TextBox txtStartDate = (TextBox) PreviousPage.FindControl("txtStartDate ");

...

}

At this point the target page does not have any knowledge of the source page. The PreviousPage property is of the type Page. For accessing controls using FindControl, the developer has to presume a certain structure in the source web form. This approach using FindControl has a few limitations. FindControl is dependent on the developer to provide the ids of the controls to access. The code will stop working if the control id is changed in the source web form. The FindControl method can retrieve controls only within the current container. If you need to access a control within another control, you need to first get a reference to the parent control.

Access source page info within the posted page: @PreviousPageType Directive

There is another more direct option to get access to the source page controls if the source page is pre-determined. The @PreviousPageType directive can be used in the target page to strongly type the source page. The directive specifies the source page using either the VirtualPath attribute or the TypeName attribute. The PreviousPage property then returns a strongly typed reference to the source page. It allows access to the public properties of the source page.

SourcePage.aspx:

<form runat="server" >
...
<asp:textbox runat="server" id="txtFirstName"/>
<asp:textbox runat="server" id="txtLastName"/>
<asp:button runat="server" id="btnViewReport" Text="View Report" PostbackURL="~/targetpage.aspx" />
...

public string FirstName

{

get { return txtFirstName.Text; }

}

...

TargetPage.aspx

<%@ PreviousPageType VirtualPath="sourcepage.aspx" %>

string strFirstName;
strFirstName = PreviousPage.FirstName //Strongly Typed PreviousPage allows direct access to the public properties of the source page.

Access source page info within the posted page: @Reference Directive

A third option to access the source page in a strongly typed fashion from the target page is to include an @Reference directive to the source page in the target page and then cast the PreviousPage property to the type of the source page.

Detect Cross Page PostBacks: IsCrossPagePostBack Property

When the source page cross-posts back to the target page, and the target page accesses the source page, the source page is reloaded in memory and goes through all the life cycle stages except the rendering. This version of the source page object is used by the target page to access information on the source page.

The IsCrossPagePostBack property in the source page indicates if it is being reloaded in memory in response to a PreviousPage reference from a target page.

Page A cross postback to Page B

Page B accesses the PreviousPage : Page A is reloaded in memory and the IsCrossPostBack property on this object has the value "true".

The IsCrossPagePostBack property can be used in the source page to prevent un-necessary processing from repeating when the page is being reloaded for the PreviousPage reference.

The PreviousPage.IsCrossPagePostBack property can be used to deduce if the current page has been loaded as a result of a cross page postback.

Validations

If the Source Page has any Validator controls, the source page will need to have valid input when it has cross posted to the target page. The target page can contain the validation check for PreviousPage.IsValid to catch invalid submissions to the source page.

Usage Scenarios

Previous limitations restricted the postback to the self page in ASP.Net 1.1. In ASP.Net 2.0, you can use cross-page post backs to post to a different web page, resulting in more intuitive, structured and maintainable code.

Example - A web form collects criteria for a web-based report (such as Report Type, Report Start Date and Report End Date) and the form is cross page posted to another web form which generates the report based on the parameters passed in the previous page.

A typical use for cross page postback is where you need a page to post to different pages by clicking on different button controls in the same form. The target page is specified with each button control, allowing postbacks to various forms.

When posting across applications, cross page postbacks allow access to the posted form data, but do not provide access to the source page's controls and viewstate.

Mackay's Moral: Nature is full of examples of teamwork. Teamwork should be part of your nature.

2008-07-10T23:01:00.000-07:00

Stand together or fall apart
The huge redwood trees in California are considered to be the tallest trees in the world. Some of them are 300 feet high and more than 2,500 years old. One would think that trees so large would have a tremendous root system reaching down hundreds of feet into the earth. Not true. The redwoods actually have a very shallow root system, but they all intertwine. They don't stand alone, for all the trees support and protect each other. When the storms come or the winds blow, the redwoods stand together.
There is strength in numbers.
To drive home the power of teamwork and sticking together, I sometimes do a visual exercise during my speeches to corporate America, as well as in-house for our salesforce and employees. I hold up a bundle of six pencils and try to break them in the air and then over my knee. The average person can't break the bundle. Then I take one pencil out and snap it in two easily. I point out that if you help each other, you will be like the bundle of pencils. No one can break you apart. But if you are divided among yourselves, you will be broken as easily as a single pencil.
It's a hard lesson for us, but unity consistently produces greater results than individual endeavors. Teamwork divides the effort and multiplies the effect.
In a pulling contest at a county fair, the first place horse ended up moving a sled weighing 4,500 pounds. The second place finisher pulled 4,000 pounds. The owners of the two horses decided to see what these horses could pull together. They hitched them up and found that the team could move 12,000 pounds.
By working separately, the two horses were good for only 8,500 pounds. However, when coupled together, their synergism produced an added 3,500 pounds!
And what about the farmer who grew award-winning corn? Each year he entered his corn in the state fair where it won a blue ribbon. One year a newspaper reporter interviewed him and learned something interesting about how he grew it.
The reporter discovered that the farmer shared his seed corn with his neighbors. "How can you afford to share your best seed corn with your neighbors when they are entering corn in competition with yours each year?" the reporter asked.
"Why sir," said the farmer, "did you know that the wind picks up pollen from the ripening corn and swirls it from field to field. If my neighbors grow inferior corn, cross-pollination will steadily degrade the quality of my corn. If I am to grow good corn, I must help my neighbors grow good corn."
June marks my wedding anniversary, so the next story is timely for me. Many years ago in Austria they had a custom that helped villagers size up the future happiness of a newly married couple.
After the wedding in the local church, the village women would escort the bride and groom to a nearby forest and stand them before a large tree. They would then hand the young couple a two-handled bucksaw and ask that they use it to cut the tree down.
The closer the cooperation between the man and wife, the shorter the time it took for the tree to come down. And the older villagers wisely reasoned that, the shorter the time, the happier the young couple would be because they had learned that most valuable of marital lessons—teamwork!
Phil Jackson, the highly successful coach of the Los Angeles Lakers professional basketball team, frequently reads poetry to his players. To inspire his players on the subject of teamwork, he once read the following lines from Kipling's 1895 poem "The Law of the Jungle":
Now this is the Law of the Jungle —
As old and as true as the sky;
And the Wolf that shall keep it may prosper,
But the Wolf that shall break it must die.
As the creeper that girdles the tree-trunk
The Law runneth forward and back —
But the strength of the Pack is the Wolf,
And the strength of the Wolf is the Pack.
Mackay's Moral: Nature is full of examples of teamwork. Teamwork should be part of your nature.

Dynamically loading loading external JavaScript or CSS files in Javascript using DOM object.

2008-07-10T07:15:00.000-07:00

To load a .js or .css file dynamically, in a nutshell, it means using DOM methods to first create a swanky new "SCRIPT" or "LINK" element, assign it the appropriate attributes, and finally, use element.appendChild() to add the element to the desired location within the document tree.

function loadjscssfile(filename, filetype){
if (filetype=="js"){ //if filename is a external JavaScript file
var fileref=document.createElement('script')
fileref.setAttribute("type","text/javascript")
fileref.setAttribute("src", filename)
}
else if (filetype=="css"){ //if filename is an external CSS file
var fileref=document.createElement("link")
fileref.setAttribute("rel", "stylesheet")
fileref.setAttribute("type", "text/css")
fileref.setAttribute("href", filename)
}
if (typeof fileref!="undefined")
document.getElementsByTagName("head")[0].appendChild(fileref)
}

loadjscssfile("myscript.js", "js") //dynamically load and add this .js file
loadjscssfile("javascript.php", "js") //dynamically load "javascript.php" as a JavaScript file
loadjscssfile("mystyle.css", "css") ////dynamically load and add this .css file

Dotnet-Interviews: Can any one solve this Puzzle / Problem in C#.NET

2008-07-02T03:41:00.000-07:00

Dotnet-Interviews: Can any one solve this Puzzle / Problem in C#.NET

How to register or unregister a DLL?

2008-06-30T04:40:00.000-07:00

Register or unregister a DLL.

Syntax
REGSVR32 [/U] [/S] [/C] [/I:[Command_Line]] DLL_Name

REGSVR32 [/U] [/S] [/C] /N /I:[Command_Line] DLL_Name
Key

/u Unregister Server.
/s Silent - no dialogue boxes.
/c Console output.
/n Don't call DllRegisterServer
/i Call DllInstall (or DllUninstall if /u is specified)
Command_Line An optional command line for DllInstall
Examples

Unregister (disable) XP Zip folders
REGSVR32 /u C:\Windows\System32\zipfldr.dll

Unregister (Disable) CAB file viewer:
REGSVR32 /u C:\Windows\System32\cabview.dll

Register (enable) XP Zip folders
REGSVR32 zipfldr.dll

Register (enable) CAB file viewer:
REGSVR32 cabview.dll

Register Windows Update DLLs (for those times when XP repair breaks Windows Update)
regsvr32 /s wuapi.dll

Different class and member Access modifiers / modifiers in C# and VB.NET?

2008-06-26T10:10:00.000-07:00

	C#	VB
Class cannot be inherited (cannot be a base class).	Sealed	NotInheritable
Class cannot be instantiated but only used as based class and/or with abstract methods.	Abstract	MustInherit
For class members: member is accessible only from the class in which it is declared. For classes: only allowed on nested classes to restrict access to the nested class to the containing class..	Private	Private
For class members: member is accessible only from types defined in the same assembly. For classes: class is accessible only from types in the same assembly.	Internal	Friend
For members: member is accessible from the class in which it is declared and from any class derived from that class.	Protected	Protected
Combines the access of Protected and Internal for a class member	Protected Internal	Protected Friend
Access is not restricted.	Public	Public
Hides a member inherited from a base class.	New	Shadows

Insight of new version of Internet Explorer IE 8

2008-06-02T22:20:00.000-07:00

Microsoft has kept development of Internet Explorer 8 pretty quiet, but already the next major version of the most widely-used browser is available for downloading in a beta version.

While the focus of IE 7 was on security and the incorporation of a tabbed interface, version 8's main features center on stability and usability.

In terms of stability, IE 8's new automatic crash recovery feature is designed to solve one major problem that most IE users know all too well. Today, when an IE window or tab freezes or crashes, other browsers instances or tabs will likely become inoperable as well.

Automatic crash recovery does a better job of isolating instances of the IE browser - or separate tabs within the same browser - so that one stalled browser or tab can be terminated without affecting any other.

If a crash does bring down the entire browser, automatic crash recovery will attempt to restore the browser to its previous state - including all open tabs - the next time you open it.

Greater stability is fine - but ultimately boring. Luckily, that's not all IE 8 has going for it. The new browser's usability features will generate the most buzz - and are likely to tempt lots of folks to give IE 8 a try.

The new Activities feature, for instance, attempts to save you a lot of times by cutting down on the number of separate sites that you have to visit to accomplish a task. In essence, the Activities feature allows you to invoke the essential services offered on separate sites without ever leaving the page you're currently on.

Let's say, for example, that you're reading a web page and you see an address for a restaurant you'd like to visit.

Today, in order to get directions to that address, you would probably go to a mapping site and type or paste the address in and then wait for the service to provide you with a map from, say, your apartment to the restaurant.

The process is time-consuming and involves at least two browser windows and tabs, plus a bit of copying a pasting.

With IE 8's Activities feature, when you select the address, a small Activities button appears next to your mouse cursor. Clicking that Activities button brings up a context-sensitive menu of possible activities, with one of the options being the ability to map the tool using your favorite mapping site.

Selecting that mapping option actually invokes the mapping site in a smaller preview window inside the current browser tab.

Another Activity might pull from a review site of restaurants, allowing you to see what others have said about the restaurant without your having to visit another site.

The Activities feature was also created with a nod toward the growing popularity of social networking sites. Just as you can pull services from other sites, the Activities feature also allows you to push information to popular networking sites such as Facebook and Digg.

If you want to refer a friend to the page from which you got the address for the restaurant, for instance, you can select the Send to Facebook option on the Activities menu, and IE 8 will log you into Facebook, send the URL to Facebook, and present you with the Facebook page that allows you to add an entry.

A set of default Activities comes with the IE 8 browser, but you easily customise the service providers that appear on your Activities list.

Another time-saving feature of IE 8 is called Web Slices, which are designed to allow you to subscribe to frequently-updated portions, or "slices," of certain Web sites.

Instead of spending your time visiting three or four Web sites to get updated information from a portion of each of those sites, you would simply use Web Slices to pull that information into a single location in IE 8.

A site such as eBay, for instance, lends itself to the Web Slices feature.

Say, for instance, that you're running or watching several auctions on eBay. Typically, you would visit eBay multiple times per day to check the status of those auctions.

With Web Slices, you can instead simply subscribe to a section of the auction page by clicking a Web Slice icon that appears when you allow your mouse cursor to hover over a portion of a site that is frequently updated.

Clicking the Web Slice icon adds a new button to a Favorites bar that appears above your browser tabs. Clicking the newly-created Web Slice button on the IE 8 Favorites bar will pull the latest data from your subscribed page and show it to you in a preview window.

You can visit the page itself merely by clicking a link within the preview window.

As with Activities, Web Slice-enabled sections of sites must be made available by web site owners themselves. The code for doing so is fairly simple and non-proprietary, however, so it will likely simply be a matter of time before many sites become "IE 8 aware" and users start seeing the Activities and Web Slices icons as they surf their favorite sites.

Download IE8 beta version here

HTML DOM Navigator Object

2008-06-02T03:37:00.000-07:00

Navigator Object

The Navigator object is actually a JavaScript object, not an HTML DOM object.

The Navigator object is automatically created by the JavaScript runtime engine and contains information about the client browser.

IE: Internet Explorer, F: Firefox, O: Opera.

Navigator Object Collections

Collection	Description	IE	F	O
plugins[]	Returns a reference to all embedded objects in the document	4	1	9

Navigator Object Properties

Property	Description	IE	F	O
appCodeName	Returns the code name of the browser	4	1	9
appMinorVersion	Returns the minor version of the browser	4	No	No
appName	Returns the name of the browser	4	1	9
appVersion	Returns the platform and version of the browser	4	1	9
browserLanguage	Returns the current browser language	4	No	9
cookieEnabled	Returns a Boolean value that specifies whether cookies are enabled in the browser	4	1	9
cpuClass	Returns the CPU class of the browser's system	4	No	No
onLine	Returns a Boolean value that specifies whether the system is in offline mode	4	No	No
platform	Returns the operating system platform	4	1	9
systemLanguage	Returns the default language used by the OS	4	No	No
userAgent	Returns the value of the user-agent header sent by the client to the server	4	1	9
userLanguage	Returns the OS' natural language setting	4	No	9

Navigator Object Methods

Method	Description	IE	F	O
javaEnabled()	Specifies whether or not the browser has Java enabled	4	1	9
taintEnabled()	Specifies whether or not the browser has data tainting enabled	4	1	9

Global Variables in JavaScript

2008-06-02T03:33:00.000-07:00

Every tutorial that I've seen describes that to create a global variable you have to declare it outside the function.

var myvar = 5; function myFunction()    alert(myvar); // 5 }

And this is the way I've been doing it for years. The problem is, I've never been particularly happy about this. It never felt self contained. Then I thought, "Hey, why not just attach it to the window object?" I almost feel like an idiot for not having thought of this sooner and I suspect you JavaScripters out there are thinking "well, duh".

function setValue() {     window.myValue = "test"; }  function getValue() {     alert(window.myValue); // "test" (assuming setValue has run) }

A quick search via Google revealed just how "in the dark" I've been. It turns out that when a global variable is set, it's added to the window object!

var myValue; function setValue() {     myValue = "test"; }  function getValue() {     alert(window.myValue); // yup, it's "test" } Source: http://snook.ca/archives/javascript/global_variable/

A potentially dangerous Request.Form value was detected from the client

2008-05-27T01:32:00.000-07:00

More details at ASP.Net site. At that site you also get some solutions, and I have read on the web that many people suggests changing web.config. That's a bad solution since it will affect all pages on your site.

Instead add a tag validateRequest="false" into the Page-directive on top of the page you want users to be able to input HTML and script tags.

ByRef vs ByVal

2008-05-19T02:07:00.000-07:00

ByRef and ByVal

When getting the value of a variable from a procedure or function parameter you have two ways to request it. Either you can request for it to be passed ByRef (default), or ByVal.

Passing ByVal
Private Sub TestSub(ByVal strPath As String)

Passing ByRef
Private Sub TestSub(ByRef strPath As String) ' or just
Private Sub TestSub(strPath As String)

When you pass ByVal, Visual Basic passes a copy of the variable to the procedure. This way the procedure gets the value, but any changes it makes will not affect the original variable.

When you pass ByRef, Visual Basic passes a pointer to the procedure. This is a reference so that the procedure knows where to find the variable in the memory. Any changes the procedure makes to this variable will effect the original one, as they are the same thing, however the variable does not need to be declared as public if you were wanting the procedure to access the variabl any other way. The following example shows the differences:

Sub Form_Load() Dim strTest As String '// fill the variable strTest = "Hello from Form_Load" '// call the procedure Call TestSub(strTest) '// display a message box containing the value of strTest Msgbox strTest End Sub '// TestSub procedure when passing ByVal Sub TestSub(ByVal strString As String) strString = "Hello from TestSub" '// when control returns to Form_Load, no changes will have '// been made to strTest End Sub '// TestSub procedure when passing ByRef Sub TestSub(ByRef strString As String) strString = "Hello from TestSub" '// when control returns to Form_Load, the value of '// strTest will have changed to Hello from TestSub End Sub

Note that when you are passing a variable ByRef, it must be declared as a specific datatype (ie string). Otherwise, VB cannot pass a pointer to it. If you do not do this, you will get a compile error:

ByRef Argument Type Mismatch.

This does not occur when passing ByVal. For example, the code below will produce a compile error when you press Command1:

Private Function TestFunction(ByRef sString As String) sString = sString & vbCrLf End Function Private Sub Command1_Click() Dim sTestString TestFunction sTestString End Sub

while, the code below would not, as you have explicitly declared sTestString As String.

Private Function TestFunction(ByRef sString As String) sString = sString & vbCrLf End Function Private Sub Command2_Click() Dim sTestString As String TestFunction sTestString End Sub

Developers born Brave to handle any situation

2008-05-16T05:29:00.000-07:00

Bulk Insert Into SQL SERVER from CSV / text file

2008-05-15T23:21:00.000-07:00

This is very common request recently - How to import CSV file into SQL Server? How to load CSV file into SQL Server Database Table? How to load comma delimited file into SQL Server? Let us see the solution in quick steps.

CSV stands for Comma Separated Values, sometimes also called Comma Delimited Values.

Create TestTable

USE TestData GO CREATE TABLE CSVTest

(ID INT,FirstName VARCHAR(40),LastName VARCHAR(40),BirthDate SMALLDATETIME) GO

Create CSV file in drive C: with name csvtest.txt with following content. The location of the file is C:\csvtest.txt

1,James,Smith,19750101 2,Meggie,Smith,19790122 3,Robert,Smith,20071101 4,Alex,Smith,20040202

Now run following script to load all the data from CSV to database table. If there is any error in any row it will be not inserted but other rows will be inserted.

BULK INSERT CSVTest FROM ‘c:\csvtest.txt’ WITH(FIELDTERMINATOR = ‘,’,ROWTERMINATOR = ‘\n’) GO

Check the content of the table.

SELECT *     FROM CSVTest GO

Drop the table to clean up database.

SELECT *     FROM CSVTest GO

ASP.NET 2.0 and "Validation of ViewState Mac failed" exception

2008-05-15T23:12:00.000-07:00

If you get this Exception

[HttpException (0x80004005): Validation of viewstate MAC failed. If this application is hosted by a Web Farm or cluster, ensure that <machineKey> configuration specifies the same validationKey and validation algorithm. AutoGenerate cannot be used in a cluster.]

and

you know *for sure* that you aren't using a web farm
it seems that it appears when using built-in databound controls such as GridView, DetailsView or FormView which utilize DataKeyNames.
it appears if you have a large page which loads slowly for any reason

If following preconditions are true and you click a postbacking control/link while the Page hasn't loaded completely, you might get the "Validation of ViewState MAC failed" exception. In this case be sure to check following post on ASP.NET Forums where this has been discussed quite thoroughly : http://forums.asp.net/1173230/ShowPost.aspx

It appears because GridView using DataKeyNames requires ViewState to be encrypted. And when ViewState is encrypted, Page adds <input type="hidden" name="__VIEWSTATEENCRYPTED" id="__VIEWSTATEENCRYPTED" value="" /> field just before closing of the <form> tag. But this hidden field might not bet yet rendered to the browser with long-running pages, and if you make a postback before it "gets down", browser initiates postback without this field (in form post collection)

End result is that if this field is omitted on postback, Page doesn't "know" that viewstate is encrypted and causes the prementioned Exception. E.g Page expects to be fully-loaded before you can make a postback. And by the way similar problem is with event validation since __EVENTVALIDATION field is also rendered on the end of the form.

A way to overcome the problem is to set in web.config

Just note the security implications of these!

Useful META TAGS Table of Contents

2008-05-14T22:37:00.000-07:00

Note the keywords "HTTP-EQUIV", "Name" and "Content" are case-insensitive. Their values are also case-insensitive.

Tag Name	Example(s)	Description
Author	<META NAME="AUTHOR" CONTENT="Tex Texin">	The author's name.
cache-control	<META HTTP-EQUIV="CACHE-CONTROL" CONTENT="NO-CACHE">	HTTP 1.1. Allowed values = PUBLIC \| PRIVATE \| NO-CACHE \| NO-STORE. Public - may be cached in public shared caches Private - may only be cached in private cache no-Cache - may not be cached no-Store - may be cached but not archived The directive CACHE-CONTROL:NO-CACHE indicates cached information should not be used and instead requests should be forwarded to the origin server. This directive has the same semantics as the PRAGMA:NO-CACHE. Clients SHOULD include both PRAGMA:NO-CACHE and CACHE-CONTROL:NO-CACHE when a no-cache request is sent to a server not known to be HTTP/1.1 compliant. Also see EXPIRES. Note: It may be better to specify cache commands in HTTP than in META statements, where they can influence more than the browser, but proxies and other intermediaries that may cache information.
Content-Language	<META HTTP-EQUIV="CONTENT-LANGUAGE" CONTENT="en-US,fr">	Declares the primary natural language(s) of the document. May be used by search engines to categorize by language.
CONTENT-TYPE	<META HTTP-EQUIV="CONTENT-TYPE" CONTENT="text/html; charset=UTF-8">	The HTTP content type may be extended to give the character set. It is recommended to always use this tag and to specify the charset.
Copyright	<META NAME="COPYRIGHT" CONTENT="© 2004 Tex Texin">	A copyright statement.
DESCRIPTION	<META NAME="DESCRIPTION" CONTENT="...summary of web page...">	The text can be used when printing a summary of the document. The text should not contain any formatting information. Used by some search engines to describe your document. Particularly important if your document has very little text, is a frameset, or has extensive scripts at the top.
EXPIRES	<META HTTP-EQUIV="EXPIRES" CONTENT="Mon, 22 Jul 2002 11:12:01 GMT">	The date and time after which the document should be considered expired. An illegal EXPIRES date, e.g. "0", is interpreted as "now". Setting EXPIRES to 0 may thus be used to force a modification check at each visit. Web robots may delete expired documents from a search engine, or schedule a revisit. HTTP 1.1 (RFC 2068) specifies that all HTTP date/time stamps MUST be generated in Greenwich Mean Time (GMT) and in RFC 1123 format. RFC 1123 format = wkday "," SP date SP time SP "GMT" wkday = (Mon, Tue, Wed, Thu, Fri, Sat, Sun) date = 2DIGIT SP month SP 4DIGIT ; day month year (e.g., 02 Jun 1982) time = 2DIGIT ":" 2DIGIT ":" 2DIGIT ; 00:00:00 - 23:59:59 month = (Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec)
Keywords	<META NAME="KEYWORDS" CONTENT="sex, drugs, rock & roll">	The keywords are used by some search engines to index your document in addition to words from the title and document body. Typically used for synonyms and alternates of title words. Consider adding frequent misspellings. e.g. heirarchy, hierarchy.
PRAGMA NO-CACHE	<META HTTP-EQUIV="PRAGMA" CONTENT="NO-CACHE">	This directive indicates cached information should not be used and instead requests should be forwarded to the origin server. This directive has the same semantics as the CACHE-CONTROL:NO-CACHE directive and is provided for backwards compatibility with HTTP/1.0. Clients SHOULD include both PRAGMA:NO-CACHE and CACHE-CONTROL:NO-CACHE when a no-cache request is sent to a server not known to be HTTP/1.1 compliant. HTTP/1.1 clients SHOULD NOT send the PRAGMA request-header. HTTP/1.1 caches SHOULD treat "PRAGMA:NO-CACHE" as if the client had sent "CACHE-CONTROL:NO-CACHE". Also see EXPIRES.
Refresh	<META HTTP-EQUIV="REFRESH" CONTENT="15;URL=http://www.I18nGuy.com/index.html">	Specifies a delay in seconds before the browser automatically reloads the document. Optionally, specifies an alternative URL to load, making this command useful for redirecting browsers to other pages.
ROBOTS	<META NAME="ROBOTS" CONTENT="ALL"> <META NAME="ROBOTS" CONTENT="INDEX,NOFOLLOW"> <META NAME="ROBOTS" CONTENT="NOINDEX,FOLLOW"> <META NAME="ROBOTS" CONTENT="NONE">	CONTENT="ALL \| NONE \| NOINDEX \| INDEX\| NOFOLLOW \| FOLLOW \| NOARCHIVE" default = empty = "ALL" "NONE" = "NOINDEX, NOFOLLOW" The CONTENT field is a comma separated list: INDEX: search engine robots should include this page. FOLLOW: robots should follow links from this page to other pages. NOINDEX: links can be explored, although the page is not indexed. NOFOLLOW: the page can be indexed, but no links are explored. NONE: robots can ignore the page. NOARCHIVE: Google uses this to prevent archiving of the page. See http://www.google.com/bot.html
GOOGLEBOT	<META NAME="GOOGLEBOT" CONTENT="NOARCHIVE">	In addition to the ROBOTS META Command above, Google supports a GOOGLEBOT command. With it, you can tell Google that you do not want the page archived, but allow other search engines to do so. If you specify this command, Google will not save the page and the page will be unavailable via its cache. See Google's FAQ.

Dotnet-Interviews: What is the new type of serialization introduced in .Net 3.5

2008-05-14T03:17:00.000-07:00

Dotnet-Interviews: What is the new type of serialization introduced in .Net 3.5

Loading Multiple Versions of same Assembly

2008-05-08T04:34:00.000-07:00

In some cases where you have programmed against say a buggy assembly and have written some workaround logic for the bug in your code. With the newer version of that assembly that bug has been fixed, but due to some constraints, you can't remove your workaround code and hence can't use the new version. There is however new functionality provided by this new version which you do want to use. Hence you would need to be able to call new methods on new version and the buggy method on the old version.

With this preamble, lets get into how to get this done. There are various permutations and combinations and I will address them. At a high level the solution is in working with one version as already programmed (typically using early binding) and with another version using reflection. Do also note that the assembly loading follows probing rules as defined in .NET SDK documentation. To keep things simple, I will keep the folder path simple and not get into such diversions.

Consider this extremely critical business logic inside of a uniquely named assembly - ClassLibrary1.dll as below. Again to keep things simple, I am not showing the various "using" statements with the code. Additionally to identify which version the method is called on, I return the version# in the string itself. I can do a dynamic query for assembly version and remove this hard coding, but the recall.. our moto is simplicity at this time and focus on loading different versions and not any other aspect, hence the hard coding.

    public class Class1
    {
        public static string Method1()
        {
            return "Method 1 called on version 1.0.0.0";
        }
    }

Then there is this Winform application that invokes this static Method1 and displays the returned string in message box. To help identify if this call has happened due to early binding or reflection, I prefix the string accordingly. I build the code with version 1.0.0.0 of ClassLibrary1.dll and run the application. On invoking the method, I see a message box displaying the appropriate version#. Before we get into multiple versions, a quick discussion of what happens with private as against strong named assemblies is in order.

Weakly named library assembly (privately deployed)

If you update the version of such an assembly and redeploy it with the application, the application is able to load it without any issues. The change in just minor version to 1.1.0.0 or major version also to 2.0.0.0 doens't impact and the application works fine. Note that this is in line with basics of versioning that aren't applicable to weakly named assemblies.

Strongly named library assembly (privately deployed)

If you update the version of such an assembly and redeploy it with the applicaton, the application will give a runtime error when it tries to invoke a method of the library assembly. Due to strong naming, the version policy comes into effect and the application tries to invoked method on version against which it was complied, in this case 1.0.0.0. When it doens't finds this at runtime, it will give an error. It won't automatically start using 1.1.0.0 version. For that you need to specify the
bindingRedirect in the application configuration file.

There are multiple ways to create this configuration file. One is to do this with Visual studio itself and when the application is compiled, the config file is also complied and deployed along wih it. However if you aren't sure of the exact syntax, you can use the Microsoft .NET Framework 2.0 Configuration MMC from Administrators group. Via this you can add the specific application for configuration, then configure the specific library assembly and specify the binding policy. The configuration file generated will look something like this

<?xml version="1.0"?>

<configuration>

  <runtime>

    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">

      <dependentAssembly>

        <assemblyIdentity name="ClassLibrary1" publicKeyToken="fbc28d9ca2fc8db5" />

        <publisherPolicy apply="no" />

        <bindingRedirect oldVersion="1.0.0.0" newVersion="1.1.0.0" />

      </dependentAssembly>

    </assemblyBinding>

  </runtime>

</configuration>

To reiterate, this bindingRedirect is required only for strongly named assemblies. Once this configuration setting is in place, the application is able to load the 1.1.0.0 assembly and invoke methods on it. The same logic will work for assemblies deployed in GAC.

Let us now get on with loading of different versions of the same assembly. See the sample code below on how to achieve it.

        private void btn_Click(object sender, EventArgs e)

            string str = "early bind - ";

            str += ClassLibrary1.Class1.Method1();

            MessageBox.Show(str);

            Assembly al = Assembly.LoadFile(@"E:\Temp\old\ClassLibrary1.dll");

            Type t = al.GetType("ClassLibrary1.Class1");

            MethodInfo m = t.GetMethod("Method1");

            str = "reflection - " + (string)m.Invoke(null, null);

            MessageBox.Show(str);

When we run the application, we expect the early binding call to go to the newer version and the call via reflection to go to the older version, that we have specifically deployed in another sub-folder. We are using Assembly.LoadFile method so that we can specify a path.

One important aspect to note here is that the application will have to be compiled with the newer version of the assembly if the assembly is strongly named. If that isn't done, as discussed earlier, we will have to use a bindingRedirect configuration setting. Such setting works for all assembly load calls and will even redirect the assembly load call that we are doing via reflection and hence we will not be able to invoke methods on older version. By explicitly building the application with newer version, we don't need to the bindingRedirect configuration setting and our reflection call to earlier version will then work.

Loading assemblies from GAC

There is slight difference in the way the assembly is loaded via reflection if working against GAC. To successfully load different versions from GAC it is best to use the AssemblyName class and specify the FullName of the assembly you want to load. As we all know, FullName includes name, version number, culture and public key token.

private void btn_Click(object sender, EventArgs e)

{

string str = "early bind - ";

str += ClassLibrary1.Class1.Method1();

MessageBox.Show(str);

AssemblyName asm = new AssemblyName("ClassLibrary1, Version=1.1.0.0, Culture=neutral,
PublicKeyToken=fbc28d9ca2fc8db5");

Assembly al = Assembly.Load(asm);

Type t = al.GetType("ClassLibrary1.Class1");

MethodInfo m = t.GetMethod("Method1");

str = "reflection - " + (string)m.Invoke(null, null);

MessageBox.Show(str);

}

Needless to say that it also possible to load as many versions as you want using the option of reflection and you need not invoke any version via early binding. I have used to early binding option just to highlight a case where you are already working with a version and want to also specifically invoke methods on a different version. This also means that you can early bind to an older version and load the newer version by reflection.

While playing around with this, I also realized that one needs not worry about references added to the project. The compiler is intelligent enough to add them to the manifest only if a call is made to any method contained in the referenced assembly. If no call is made, the reference isn't included and hence the assembly won't be loaded at run time. You can easily verify this by viewing the manifest via ILDasm utility.

HTTP Status Codes that the Web Server can return

2008-05-08T02:49:00.000-07:00

HTTP Status Codes that the Web Server can return - Definitions

200 OK
301 Moved Permanently
302 Found
304 Not Modified
307 Temporary Redirect
400 Bad Request
401 Unauthorized
403 Forbidden
404 Not Found
410 Gone
500 Internal Server Error
501 Not Implemented

HTTP Status Code - 200 OK

The request has succeeded. The information returned with the response is dependent on the method used in the request.

HTTP Status Code - 301 Moved Permanently

The requested resource has been assigned a new permanent URI and any future references to this resource SHOULD use one of the returned URIs.

Test URI: /w3c/status-codes/301.asp

HTTP Status Code - 302 Found

The requested resource resides temporarily under a different URI. Since the redirection might be altered on occasion, the client SHOULD continue to use the Request-URI for future requests.

Test URI: /w3c/status-codes/302.asp

Admin Note: 2005-03-14 - During the past several months, many discussions have been taking place in the search engine marketing communities concerning what many refer to as pagejacking. What you are about to read concerns everyone who has a website online, this is not an isolated incident. Those who are involved with the page jacking issues may not even know that they are causing harm to those they are linking to using a 302 Found redirect. Many of the 302s are generated from exit tracking scripts.

302 Pagejacking - The 302 Page Hijacking Exploit by Claus Schmidt

HTTP Status Code - 304 Not Modified

If the client has performed a conditional GET request and access is allowed, but the document has not been modified, the server SHOULD respond with this status code. The 304 response MUST NOT contain a message-body, and thus is always terminated by the first empty line after the header fields.

HTTP Status Code - 307 Temporary Redirect

The requested resource resides temporarily under a different URI. Since the redirection MAY be altered on occasion, the client SHOULD continue to use the Request-URI for future requests. This response is only cacheable if indicated by a Cache-Control or Expires header field.

Test URI: /w3c/status-codes/307.asp

HTTP Status Code - 400 Bad Request

The request could not be understood by the server due to malformed syntax. The client SHOULD NOT repeat the request without modifications.

HTTP Status Code - 401 Unauthorized

The request requires user authentication. The response MUST include a WWW-Authenticate header field containing a challenge applicable to the requested resource.

HTTP Status Code - 403 Forbidden

The server understood the request, but is refusing to fulfill it. Authorization will not help and the request SHOULD NOT be repeated.

HTTP Status Code - 404 Not Found

The server has not found anything matching the Request-URI. No indication is given of whether the condition is temporary or permanent.

Test URI: /w3c/status-codes/404.asp

HTTP Status Code - 410 Gone

The requested resource is no longer available at the server and no forwarding address is known. This condition is expected to be considered permanent. Clients with link editing capabilities SHOULD delete references to the Request-URI after user approval.

If the server does not know, or has no facility to determine, whether or not the condition is permanent, the status code 404 Not Found SHOULD be used instead. This response is cacheable unless indicated otherwise.

Test URI: /w3c/status-codes/410.asp

HTTP Status Code - 500 Internal Server Error

The server encountered an unexpected condition which prevented it from fulfilling the request.

HTTP Status Code - 501 Not Implemented

The server does not support the functionality required to fulfill the request. This is the appropriate response when the server does not recognize the request method and is not capable of supporting it for any resource.

W3C References

Data Types of SQL SERVER 2005

2008-05-07T05:11:00.000-07:00

Exact numerics

Type	From	To
bigint	-9,223,372,036,854,775,808	9,223,372,036,854,775,807
int	-2,147,483,648	2,147,483,647
smallint	-32,768	32,767
tinyint	0	255
bit	0	1
decimal	-10^38 +1	10^38 –1
numeric	-10^38 +1	10^38 –1
money	-922,337,203,685,477.5808	+922,337,203,685,477.5807
smallmoney	-214,748.3648	+214,748.3647

numeric and decimal are Fixed precision and scale data types and are functionally equivalent.

Approximate numerics

Type	From	To
float	-1.79E + 308	1.79E + 308
real	-3.40E + 38	3.40E + 38

datetime and smalldatetime

Type	From	To
datetime (3.33 milliseconds accuracy)	Jan 1, 1753	Dec 31, 9999
smalldatetime (1 minute accuracy)	Jan 1, 1900	Jun 6, 2079

Character Strings

Type	Description
char	Fixed-length non-Unicode character data with a maximum length of 8,000 characters.
varchar	Variable-length non-Unicode data with a maximum of 8,000 characters.
varchar(max)	Variable-length non-Unicode data with a maximum length of 2³¹ characters (SQL Server 2005 only).
text	Variable-length non-Unicode data with a maximum length of 2,147,483,647 characters.

Unicode Character Strings

Type	Description
nchar	Fixed-length Unicode data with a maximum length of 4,000 characters.
nvarchar	Variable-length Unicode data with a maximum length of 4,000 characters.
nvarchar(max)	Variable-length Unicode data with a maximum length of 2³⁰ characters (SQL Server 2005 only).
ntext	Variable-length Unicode data with a maximum length of 1,073,741,823 characters.

Binary Strings

Type	Description
binary	Fixed-length binary data with a maximum length of 8,000 bytes.
varbinary	Variable-length binary data with a maximum length of 8,000 bytes.
varbinary(max)	Variable-length binary data with a maximum length of 2³¹ bytes (SQL Server 2005 only).
image	Variable-length binary data with a maximum length of 2,147,483,647 bytes.

Other Data Types

sql_variant: Stores values of various SQL Server-supported data types, except text, ntext, and timestamp.
timestamp: Stores a database-wide unique number that gets updated every time a row gets updated.
uniqueidentifier: Stores a globally unique identifier (GUID).
xml: Stores XML data. You can store xml instances in a column or a variable (SQL Server 2005 only).
cursor: A reference to a cursor.
table: Stores a result set for later processing.

Source: http://www.teratrax.com/sql_guide/data_types/sql_server_data_types.html

All types of format strings

2008-05-06T06:27:00.000-07:00

Strings

There really isn’t any formatting within a strong, beyond it’s alignment. Alignment works for any argument being printed in a String.Format call.

Sample	Generates
String.Format(”->{1,10}<-”, “Hello”);	-> Hello<-
String.Format(”->{1,-10}<-”, “Hello”);	->Hello <-

Numbers

Basic number formatting specifiers:

Specifier	Type	Format	Output (Passed Double 1.42)	Output (Passed Int -12400)
c	Currency	{0:c}	$1.42	-$12,400
d	Decimal (Whole number)	{0:d}	System.FormatException	-12400
e	Scientific	{0:e}	1.420000e+000	-1.240000e+004
f	Fixed point	{0:f}	1.42	-12400.00
g	General	{0:g}	1.42	-12400
n	Number with commas for thousands	{0:n}	1.42	-12,400
r	Round trippable	{0:r}	1.42	System.FormatException
x	Hexadecimal	{0:x4}	System.FormatException	cf90

Custom number formatting:

Specifier	Type	Example	Output (Passed Double 1500.42)	Note
0	Zero placeholder	{0:00.0000}	1500.4200	Pads with zeroes.
#	Digit placeholder	{0:(#).##}	(1500).42
.	Decimal point	{0:0.0}	1500.4
,	Thousand separator	{0:0,0}	1,500	Must be between two zeroes.
,.	Number scaling	{0:0,.}	2	Comma adjacent to Period scales by 1000.
%	Percent	{0:0%}	150042%	Multiplies by 100, adds % sign.
e	Exponent placeholder	{0:00e+0}	15e+2	Many exponent formats available.
;	Group separator	see below

The group separator is especially useful for formatting currency values which require that negative values be enclosed in parentheses. This currency formatting example at the bottom of this document makes it obvious:

Dates

Note that date formatting is especially dependant on the system’s regional settings; the example strings here are from my local locale.

Specifier	Type	Example (Passed System.DateTime.Now)
d	Short date	10/12/2002
D	Long date	December 10, 2002
t	Short time	10:11 PM
T	Long time	10:11:29 PM
f	Full date & time	December 10, 2002 10:11 PM
F	Full date & time (long)	December 10, 2002 10:11:29 PM
g	Default date & time	10/12/2002 10:11 PM
G	Default date & time (long)	10/12/2002 10:11:29 PM
M	Month day pattern	December 10
r	RFC1123 date string	Tue, 10 Dec 2002 22:11:29 GMT
s	Sortable date string	2002-12-10T22:11:29
u	Universal sortable, local time	2002-12-10 22:13:50Z
U	Universal sortable, GMT	December 11, 2002 3:13:50 AM
Y	Year month pattern	December, 2002

The ‘U’ specifier seems broken; that string certainly isn’t sortable.

Custom date formatting:

Specifier	Type	Example	Example Output
dd	Day	{0:dd}	10
ddd	Day name	{0:ddd}	Tue
dddd	Full day name	{0:dddd}	Tuesday
f, ff, …	Second fractions	{0:fff}	932
gg, …	Era	{0:gg}	A.D.
hh	2 digit hour	{0:hh}	10
HH	2 digit hour, 24hr format	{0:HH}	22
mm	Minute 00-59	{0:mm}	38
MM	Month 01-12	{0:MM}	12
MMM	Month abbreviation	{0:MMM}	Dec
MMMM	Full month name	{0:MMMM}	December
ss	Seconds 00-59	{0:ss}	46
tt	AM or PM	{0:tt}	PM
yy	Year, 2 digits	{0:yy}	02
yyyy	Year	{0:yyyy}	2002
zz	Timezone offset, 2 digits	{0:zz}	-05
zzz	Full timezone offset	{0:zzz}	-05:00
:	Separator	{0:hh:mm:ss}	10:43:20
/	Separator	{0:dd/MM/yyyy}	10/12/2002

Enumerations

Specifier	Type
g	Default (Flag names if available, otherwise decimal)
f	Flags always
d	Integer always
x	Eight digit hex.

Some Useful Examples

String.Format(”{0:$#,##0.00;($#,##0.00);Zero}”, value);

This will output “$1,240.00″ if passed 1243.50. It will output the same format but in parentheses if the number is negative, and will output the string “Zero” if the number is zero.

String.Format(”{0:(###) ###-####}”, 8005551212);

This will output “(800) 555-1212″.

Script to make Web page unprintable

2008-04-28T04:54:00.000-07:00

If you want it to be unprintable, you could stop newbie users from
printing directly from the page by putting:

Between the <head> tags.

Script to disable right click on a web page

2008-04-28T04:53:00.000-07:00

Here is the script

document.onmousedown=right;
if (document.layers) window.captureEvents(Event.MOUSEDOWN);
window.onmousedown=right;
// End -->

</script>

Difference between TOP clause in SQL 2000 and SQL 2005

2008-04-23T06:24:00.000-07:00

Generally TOP clause is used to perform SELECT on top n results. This feature of TOP is extended in SQL 2005 so that we can also use expression apart from int, bigint and percent to perform query and also extended to be used in UPDATE and DELETE statements.

In SQL 2000

syntax: select Top N [Percent]

EX:

select Top 10 * from TableName

select Top 10 Percent * from TableName

n specifies how many rows are returned. If PERCENT is not specified, n is the number of rows to return. If PERCENT is specified, n is the percentage of the result set rows to return

Drawbacks:

We could not parameterize.

It will work only for select statements.

If we want to restrict the number of rows affected by a select at runtime, or restrict the rows affected by an update or delete you had to explicitly describe the rows using a join or where clause, or you could cheat a bit by using ROWCOUNT, like this

set rowcount 10 delete from table where payratefieldname=1 set rowcount 0

It will work but the risk is if for some reason rowcount is not set to 0 then the other statements will also restricted to 10.

All these drawbacks are overcome in SQL 2005 by introducing Expression in syntax.

In SQL 2005

syntax: select Top (Expression) [Percent]

EX:

Is the numeric expression that specifies the number of rows to be returned. expression is implicitly converted to a float value if PERCENT is specified; otherwise, it is converted to bigint.

Ex:

select Top 10 * from TableName

select Top 10 Percent * from TableName

or we can set at runtime as

Declare @ int

SET @topNum = 10

select TOP (@topNum) * from

For select statements you must specify parentheses if you are passing a parameter, otherwise they are optional

Select Top (@topNum) * from TableName Select Top 10 * from TableName

When doing an update or delete, you have to use the parentheses in both cases:

Delete Top (@topNum) from employeesDelete Top (10) from TableName update Top (@topNum) TableName set fieldname = @fieldvalue  update Top (10) from employees set fieldname = @fieldvalue This is nice tricky change introduced in SQL 2005

Detecting a Client's screen resolution and color depth in ASP.NET/Javascript

2008-04-23T02:52:00.000-07:00

At times you might want to know how much screen real estate a user has before opening several new browser windows. You also might want to find out if they have a high-color display capable of showing a detailed color image. The following code shows how to learn the user's screen real estate and color depth. The total screen size includes unusable areas like the icon tray on Windows or the menubar on the Mac. The available screen size attributes subtract these system-reserved areas from the total screen size. For multi-screen systems, Internet Explorer will return the size of the monitor it is on, while Netscape returns the size of both monitors combined.

  <HTML> <HEAD> 	<TITLE>Detecting the user's hardware</TITLE> </HEAD> <BODY BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000FF" ALINK="#6600FF" VLINK="#CC0000"> <SCRIPT LANGUAGE="JavaScript1.2" TYPE="text/javascript"> 	<!-- 	document.writeln("Total Screen size = ", screen.width, " x ", screen.height); 	document.writeln("<P>"); 	document.writeln("Available Screen size = ", screen.availWidth, " x ", screen.availHeight); 	document.writeln("<P>"); 	document.writeln("Color depth = ", screen.colorDepth); 	//--> </SCRIPT> </BODY> </HTML>

Retrieving all Server Environment variable values

2008-04-23T01:18:00.000-07:00

How to retrieve all Server Environment variables at one go. Just place
this code in .aspx page run it.

<div>
<table width="70%" align="center">
<tr bgcolor="#FF9900">
<td width="25%" align="center">
ServerVariable:
</td>
<td width="75%">
Value
</td>
</tr>
<% foreach(string Item in Request.ServerVariables){ %>
<tr>
<td width="25%">
<%= Item %>
</td>
<td width="75%">
<%=Request.ServerVariables[Item]%>
</td>
</tr>
<% } %>
</table>
</div>

Complete list of server environment variables

2008-04-23T01:10:00.000-07:00

Following is the table containing a list of server environment variables.

Using:

VB: Request.ServerVariables("Variable")

C#: Request.ServerVariables["Variable"]

Variable	Description
`ALL_HTTP`	All HTTP headers sent by the client.
`ALL_RAW`	Retrieves all headers in raw form. The difference between `ALL_RAW` and `ALL_HTTP` is that `ALL_HTTP` places an HTTP_ prefix before the header name and the header name is always capitalized. In `ALL_RAW` the header name and values appear as they are sent by the client.
`APPL_MD_PATH`	Retrieves the metabase path for the Application for the ISAPI DLL.
`APPL_PHYSICAL_PATH`	Retrieves the physical path corresponding to the metabase path. IIS converts the `APPL_MD_PATH` to the physical (directory) path to return this value.
`AUTH_PASSWORD`	The value entered in the client's authentication dialog. This variable is available only if Basic authentication is used.
`AUTH_TYPE`	The authentication method that the server uses to validate users when they attempt to access a protected script.
`AUTH_USER`	The name of the user as it is derived from the authorization header sent by the client, before the user name is mapped to a Windows account. This variable is no different from `REMOTE_USER`. If you have an authentication filter installed on your Web server that maps incoming users to accounts, use `LOGON_USER` to view the mapped user name.
`CERT_COOKIE`	Unique ID for client certificate, returned as a string. Can be used as a signature for the whole client certificate.
`CERT_FLAGS`	bit0 is set to 1 if the client certificate is present. bit1 is set to 1 if the cCertification authority of the client certificate is invalid (it is not in the list of recognized CAs on the server).
`CERT_ISSUER`	Issuer field of the client certificate (O=MS, OU=IAS, CN=user name, C=USA).
`CERT_KEYSIZE`	Number of bits in Secure Sockets Layer connection key size. For example, 128.
`CERT_SECRETKEYSIZE`	Number of bits in server certificate private key. For example, 1024.
`CERT_SERIALNUMBER`	Serial number field of the client certificate.
`CERT_SERVER_ISSUER`	Issuer field of the server certificate.
`CERT_SERVER_SUBJECT`	Subject field of the server certificate.
`CERT_SUBJECT`	Subject field of the client certificate.
`CONTENT_LENGTH`	The length of the content as given by the client.
`CONTENT_TYPE`	The data type of the content. Used with queries that have attached information, such as the HTTP queries GET, POST, and PUT.
`GATEWAY_INTERFACE`	The revision of the CGI specification used by the server. The format is CGI/revision.
`HTTP_`<`HeaderName`>	The value stored in the header `HeaderName`. Any header other than those listed in this table must be prefixed by HTTP_ in order for the `ServerVariables` collection to retrieve its value. Note The server interprets any underscore (_) characters in `HeaderName` as dashes in the actual header. For example if you specify `HTTP_MY_HEADER`, the server searches for a header sent as MY-HEADER.
`HTTP_ACCEPT`	Returns the value of the Accept header.
`HTTP_ACCEPT_LANGUAGE`	Returns a string describing the language to use for displaying content.
`HTTP_COOKIE`	Returns the cookie string that was included with the request.
`HTTP_HOST`	Returns the name of the Web server. This may or may not be the same as `SERVER_NAME` depending on type of name resolution you are using on your Web server (IP address, host header).
`HTTP_REFERER`	Returns a string that contains the URL of the page that referred the request to the current page using an HTML <A> tag. Note that the URL is the one that the user typed into the browser address bar, which may not include the name of a default document. If the page is redirected, `HTTP_REFERER` is empty. `HTTP_REFERER` is not a mandatory member of the HTTP specification.
`HTTP_USER_AGENT`	Returns a string describing the browser that sent the request.
`HTTPS`	Returns ON if the request came in through secure channel (SSL) or it returns OFF if the request is for a non-secure channel.
`HTTPS_KEYSIZE`	Number of bits in Secure Sockets Layer connection key size. For example, 128.
`HTTPS_SECRETKEYSIZE`	Number of bits in server certificate private key. For example, 1024.
`HTTPS_SERVER_ISSUER`	Issuer field of the server certificate.
`HTTPS_SERVER_SUBJECT`	Subject field of the server certificate.
`INSTANCE_ID`	The ID for the IIS instance in textual format. If the instance ID is 1, it appears as a string. You can use this variable to retrieve the ID of the Web-server instance (in the metabase) to which the request belongs.
`INSTANCE_META_PATH`	The metabase path for the instance of IIS that responds to the request.
`LOCAL_ADDR`	Returns the Server Address on which the request came in. This is important on multi-homed computers where there can be multiple IP addresses bound to the computer and you want to find out which address the request used.
`LOGON_USER`	The Windows account that the user is impersonating while connected to your Web server. Use `REMOTE_USER` or `AUTH_US`<`CODE`>`E`R to view the raw user name that is contained in the request header. The only time `LOGON_USER` holds a different value than these other variables is if you have an authentication filter installed.
`PATH_INFO`	Extra path information as given by the client. You can access scripts by using their virtual path and the `PATH_INFO` server variable. If this information comes from a URL, it is decoded by the server before it is passed to the CGI script.
`PATH_TRANSLATED`	A translated version of `PATH_INFO` that takes the path and performs any necessary virtual-to-physical mapping.
`QUERY_STRING`	Query information stored in the string following the question mark (?) in the HTTP request.
`REMOTE_ADDR`	The IP address of the remote host making the request.
`REMOTE_HOST`	The name of the host making the request. If the server does not have this information, it will set `REMOTE_ADDR` and leave this empty.
`REMOTE_USER`	The name of the user as it is derived from the authorization header sent by the client, before the user name is mapped to a Windows account. If you have an authentication filter installed on your Web server that maps incoming users to accounts, use `LOGON_USER` to view the mapped user name.
`REQUEST_METHOD`	The method used to make the request. For HTTP, this is GET, HEAD, POST, and so on.
`SCRIPT_NAME`	A virtual path to the script being executed. This is used for self-referencing URLs.
`SERVER_NAME`	The server's host name, DNS alias, or IP address as it would appear in self-referencing URLs.
`SERVER_PORT`	The port number to which the request was sent.
`SERVER_PORT_SECURE`	A string that contains either 0 or 1. If the request is being handled on the secure port, then this will be 1. Otherwise, it will be 0.
`SERVER_PROTOCOL`	The name and revision of the request information protocol. The format is protocol/revision.
`SERVER_SOFTWARE`	The name and version of the server software that answers the request and runs the gateway. The format is name/version.
`URL`	Gives the base portion of the URL.

What is the difference between Class and structure’s ?

2008-04-17T06:07:00.000-07:00

Following are the key differences between them :-
√ Structure are value types and classes are reference types. So
structures use stack and classes use heap.
√ Structures members can not be declared as protected, but class members
can be. You can not do inheritance in structures.
√ Structures do not require constructors while classes require.
√ Objects created from classes are terminated using Garbage collector.
Structures are not destroyed using GC.

Difference between localization and globalization

2008-04-17T06:06:00.000-07:00

Below are the definition’s which is taken from the Microsoft glossary.
Globalization: It is the process of developing a program core whose features and code design are not solely based on a single language or locale.
Localization: The process of adapting a program for a specific local market, which includes translating the user interface, resizing dialog boxes, customizing features (if necessary), and testing results to ensure that the program still works. You can visualize globalization as more of architecture decisions. While localization is adapting your content to local market. Localization phase occurs before globalization phase.

Namespaces during localization and globalization

2008-04-17T06:05:00.000-07:00

There are two most important namespaces:-
√ System.Globalization - contains classes that define culture-related information, including the language, the country/region, the calendars in use, the format patterns for dates, currency and numbers, and the sort order for strings.
√ System.Resources - provides classes and interfaces that allow developers to create, store, and manage various culture-specific resources used in an application. With this namespace you can read a resource file and display it accordingly to the user’s culture.

Using Repeater inside a Repeater.

2008-04-17T05:49:00.000-07:00

Simply instead of the following line

<asp:repeater id="childRepeater" runat="server"                      datasource='<%# ((DataRowView)Container.DataItem)       .Row.GetChildRows("myrelation") %>' >

Use below line.

<asp:repeater id="childRepeater" runat="server"                      datasource='<%# GetChildData(databinder.Eval(Container.DataItem,"PKID")) %>' >

and in code behind file write this following function

public function GetChildData(byval pkid as long) as datatable dim dt as datatable  ' get your result in db by PKID or any other filteration return dt end function  here is the example  .... http://support.microsoft.com/default.aspx?scid=kb;en-us;306154

Coding Guidelines for C# .NET

2008-04-17T03:37:00.000-07:00

1 Capitalization Styles

Pascal Casing

This convention capitalizes the first character of each word (as in SumSal).

Camel Casing

This convention capitalizes the first character of each word except the first character of the first word. E.g. sumSal.

3 Guidelines

3.1 Naming Conventions and Style

1. Use Pascal casing for type and method names

public class SomeClass

{

public SomeMethod(){}

}

Class names must be Nouns or Noun phrases.

Name methods with Verbs or Verb phrases.

2. Use camel casing for local variable names and method arguments

int number; someNumber

void MyMethod(int someNumber)

{

}

Try to avoid abbreviations in method arguments.

3. Name interfaces with I prefix

interface IMyInterface

{ .. }

Use Pascal Casing

Page 5 of 21

start the interface name with "I" and capitalize the letter following the "I"

4. Prefix private member variables with m_

public class SomeClass

{

private int m_Number;

}

Microsoft recommends against the m_ (and the straight _) even though they did both in their code.

Use camel case.

Ex: private int _someNumber

5. Suffix custom attributes classes with Attribute.

Follow class naming conventions, but add Attribute to the end of the name

Ex: SomeNumberAttribute

6. Suffix custom exception classes with Exception.

Follow class naming conventions, but add Exception to the end of the name

Ex: SomeNumberException

7. Name methods using verb-object pair, such as ShowDialog ()
8. Methods with return values should have a name describing the value returned, such

as GetObjectState().

9. Use descriptive variable names. Avoid one-character variable names, such as i or t. Use index or temp instead.

Counting variables are preferably called i, j, k, l, m, n when used in 'trivial'

counting loops, but try using meaningful names for variables used as counters

E.g. EmpCount

Use Pascal Casing.

10. All member variables should be declared at the top, with one line separating them

from the properties or methods

public class MyClass

{

int m_Number;

string m_Name;

public void SomeMethod1(){}

public void SomeMethod2(){}

Page 6 of 21

}

11. Declare a local variable as close as possible to its first use.

12. Use meaningful namespaces such as the product name, company name, etc.

Namespace names must be nouns or noun phrases.

Use Pascal Casing no underscores.

Use CompanyName.TechnologyName as root. If you don't have

a company, use your domain name or your own initials. Note that any acronyms of

three or more letters should be pascal case (Xml instead of XML) instead of all caps

Ex:.DotNetTraining.Xml

Use hierarchical names for namespaces with dots as separation points for namespaces that are related and can be grouped together. For example consider the following:

Database - Main namespace

Database.Records - Records namespace

Database.Tables - Table functions namespace

13. Avoid fully qualified type names. Use the using statement instead.
14. Avoid putting a using statement inside a namespace.
15. Group all framework namespaces together and put custom or third party namespaces beneath.

using System;

using System. Collections;

using System.ComponentModel;

using System.Data;

using MyCompany;

using MyControls;

16. A file name should reflect the class it contains.
17. Always place an open curly brace ({) in a new line.
18. With anonymous methods mimic the code layout of a regular method, aligned with the anonymous delegate declaration.

Follow class naming conventions, but add Delegate to the end of the name

a. Comply with placing an open curly brace in a new line

delegate void SomeDelegate(string str);

//Correct:

public void InvokeMethod()

Page 7 of 21

{

SomeDelegate del = delegate(string str)

{

MessageBox.Show(str);

}

del("Hello");

}

//Avoid

public void InvokeMethod()

{

SomeDelegate del = delegate(string str){MessageBox.Show(str);};

del("Hello");

}

Varaible/Paramater Type Prefix

Basic Type	Prefix
sbyte (System.Sbyte)	sbyt
byte (System.Byte)	byt
char (System.Char)	chr
short (System.Int16)	sh
ushort (System.UInt16)	ush
bool (System.Boolean)	b
int (System.Int32)	n
uint (System.UInt32)	un
long (System.Int64)	l
ulong (System.UInt64)	ul
decimal (System.Decimal)	dc
double (System.Double)	d
float (System.Single)	f
string (System.String)	s
DateTime	dt
TimeSpan	ts
object (System.Object)	o

3.2 Comments and Embedded Documentation
1. 1. Each file shall contain a header block.

The header block must consist of a #region block containing the following copyright statement and the name of the file.

2. Use // for comments.

Page 8 of 21

3. Do not use blocks of //-------- or //********.
4. All comments shall be written in English.
5. Use XML tags for documenting types and members.

All public and protected types, methods, fields, events, delegates, etc. shall be documented using XML tags. Using these tags will allow IntelliSense to provide useful details while using the types. Also, automatic documentation generation tooling relies on these tags.

Section tags define the different sections within the type documentation.

Section Tags	Description	Location
<summary>	Short description	type or member
<remarks>	Describes preconditions and other additional information.	type or member
<param>	Describes the parameters of a method	method
<returns>	Describes the return value of a method	method
<exception>	Lists the exceptions that a method or property can throw	method, even or property
<value>	Describes the type of the data a property accepts and/or returns	property
<example>	Contains examples (code or text) related to a member or a type	type or member
<seealso>	Adds an entry to the See Also section	type or member
<overloads>	Provides a summary for multiple overloads of a method	first method in a overload list.

SECTION TAGS DESCRIPTION LOCATION

Inline tags can be used within the section tags.

Inline Tags	Description
<see>	Creates a hyperlink to another member or type
<paramref>	Creates a checked reference to a parameter

Markup tags are used to apply special formatting to a part of a section. Page 9 of 21

Markup Tags	Description
<code>	Changes the indentation policy for code examples
<c>	Changes the font to a fixed-wide font (often used with the <code> tag)
<para>	Creates a new paragraph
<list>	Creates a bulleted list, numbered list, or a table.
<b>	Bold typeface
<i>	Italics typeface

Exception:

In an inheritance hierarchy, do not repeat the documentation but use the <see> tag to refer to the base class or interface member.

6. Use #region to group non-public members.

If a class contains a large number of members, attributes, and/or properties, put all non-public members in a region. Preferably, use separate regions to split-up the private, protected, and internal members, and a region to hide all fields. It is also allowed to use the #region construct for separating the smaller auxiliary classes from the main class.

Page 10 of 21

3.3 Coding Practices
1. 1. Always use C# predefined types rather than the aliases in the System namespace.

For example:

object NOT Object

string NOT String

int NOT Int32

2. Avoid putting multiple classes in a single file.

3. A single file should only contribute types to a single namespace. Avoid having multiple namespaces in the same file.

4. Avoid files with more than 500 lines (excluding machine-generated code).

5. Lines should not exceed 80 characters.

6. Do not manually edit any machine-generated code.

7. If modifying machine-generated code, modify the format and style to match this

coding standard.

8. Avoid comments that explain the obvious.

9. Document only operational assumptions, algorithm insights etc.

10. Never hard-code a numeric value, always declare a constant instead.

11. Make only the most necessary types public, mark others as internal.

12. Always use zero-based arrays.

13. Avoid specifying a type for an enum (like long).

14. Never use goto unless in a switch statement fall-through.

15. Avoid function calls in Boolean conditional statements. Assign into local variables and check on them:

bool IsEverythingOK()

{…}

//Avoid:

if(IsEverythingOK())

{…}

//Instead:

bool ok = IsEverythingOK();

if(ok)

{…}

16. Only catch exceptions for which you have explicit handling.

Page 11 of 21

17. Avoid error code as methods return values.
18. Do not use the new inheritance qualifier. Use override instead.
19. Minimize code in application assemblies (EXE client assemblies), use class libraries instead to contain business logic.
20. Never hardcode strings that will be presented to end-users. Use resources instead.
21. Never hardcode strings that might change based on deployment such as connection strings.
22. Never use unsafe code unless when using interop.
23. Avoid multiple Main() methods in a single assembly.
24. Never assume a type supports an interface. Defensively query for that interface.

SomeType obj1;

IMyInterface obj2;

/* Some code to initialize obj1, then: */

obj2 = obj1 as IMyInterface;

if(obj2 != null)

{

obj2.Method1();

}

else

{

//Handle error in expected interface

}

25. Do not provide public or protected member variables. Use properties instead.

26. Do not provide public event member variables. Use event assessors instead.

public class MySource

{

MyDelegate m_NumberChangedEvent;

public event MyDelegate NumberChangedEvent

{

add

{

m_NumberChangedEvent + = value;

}

remove

{

m_NumberChangedEvent - = value;

}

Page 12 of 21

27. Avoid events as interface members.
28. Avoid abstract methods, use interfaces instead.
29. Always mark public and protected methods as virtual in a non-sealed class.
30. When building a long string, use StringBuilder, not string.
31. Always use a curly brace scope in an if statement, even if it conditions a single statement.
32. Always provide a static constructor when providing static member variables.
33. Avoid code that relies on an assembly running from a particular location.
34. Do not use late-binding invocation when early-binding is possible.
35. Avoid using the trinary conditional operator.
36. Use the EventsHelper class to publish events defensively.
37. Use application logging and tracing.
38. Do not use the base word to access base class members unless you wish to resolve a conflict with a subclasses member of the same name or when invoking a base class Constructor.

4 Object Lifecycle
1. 1. Declare and initialize variables close to where they are used.
2. 2. If possible, initialize variables at the point of declaration.

If you use field initialization then instance fields will be initialized before the instance constructor is called. Likewise, static fields are initialized when the static constructor is called. Notice that the compiler will always initialize any uninitialized reference variable to zero.

3. Declare each variable in a separate declaration statement.

4. Use a const field to define constant values.

Making it const ensures that memory is allocated for that item only once.

private const int maxUsers = 100;

Exception

If the value of a constant field must be calculated at run-time (in the static constructor), use a static read only field instead.

5. Set a reference field to null to tell the Garbage Collector that the object is no longer needed.

Setting reference fields to null may improve memory usage because the object involved will be unreferenced from that point on, allowing the Garbage Collector

Page 13 of 21

to clean-up the object much earlier. Please note that this recommendation should not be followed for a variable that is about to go out of scope.

6. Avoid implementing a destructor.

The use of destructors in C# is demoted since it introduces a severe performance penalty due to way the Garbage Collector works. It is also a bad design pattern to clean up any resources in the destructor since you cannot predict a which time the destructor is called (in other words, it is non-deterministic).

Notice that C# destructors are not really destructors as in C++. They are just a C# compiler feature to represent CLR Finalizers.

7. If a destructor is needed, also use GC.SuppressFinalize.

If a destructor is needed to verify that a user has called certain cleanup methods such as Close() on a IpcPeer object, call GC.SuppressFinalize in the Close() method. This ensures that the destructor is ignored if the user is properly using the class.

8. Implement IDisposable if a class uses unmanaged or expensive resources.

If a class uses unmanaged resources such as objects returned by C/C++ DLLs, or expensive resources that must be disposed of as soon as possible, you must implement the IDisposable interface to allow class users to explicitly release such resources.

9. Do not access any reference type members in the destructor.

When the destructor is called by the Garbage Collector, it is very possible that some or all of the objects referenced by class members are already garbage collected, so dereferencing those objects may cause exceptions to be thrown. Only value type members can be accessed (since they live on the stack).

4.1 Control Flow
1. 1. Do not change a loop variable inside a for loop block.

Updating the loop variable within the loop body is generally considered confusing, even more so if the loop variable is modified in more than one place.

2. Update loop variables close to where the loop condition is specified.

This makes understanding the loop much easier.

All flow control primitives (if, else, while, for, do, switch) shall be followed by a block, even if it is empty.

Please note that this also avoids possible confusion in statements of the form:

if (b1) if (b2) Foo(); else Bar(); // which ‘if’ goes with the ‘else’?

3. All switch statements shall have a default label as the last case label.

Page 14 of 21

A comment such as “no action” is recommended where this is the explicit intention. If the default case should be unreachable, an assertion to this effect is recommended.

4. Avoid multiple or conditional return statements.

One entry, one exit is a sound principle and keeps control flow simple. However, if some cases, such as when preconditions are checked, it may be good practice to exit a method immediately when a certain precondition is not met.

5. Do not make explicit comparisons to true or false.

It is usually bad style to compare a bool-type expression to true or false.

Example:

while (condition == false) // wrong; bad style

while (condition != true) // also wrong

while (booleanCondition) // OK

6. Do not access a modified object more than once in an expression.

The evaluation order of sub-expressions within an expression is defined in C#, in contrast to C or C++, but such code is hard to understand.

Example:

v[i] = ++c; // right

v[i] = ++i; // wrong: is v[i] or v[++i] being assigned to?

i = i + 1; // right

i = ++i + 1; // wrong and useless; i += 2 would be clearer

7. Do not use selection statements (if, switch) instead of a simple assignment or initialization.

Express your intentions directly. For example, rather than

bool pos;

if (val > 0)

{

pos = true;

}

else

{

pos = false;

}

or (slightly better)

bool pos = (val > 0) ? true : false;

write

Page 15 of 21

bool pos;

pos = (val > 0); // single assignment

or even better

bool pos = (val > 0); // initialization

4.2 Object Oriented Programming
1. 1. Declare all fields (data members) private.
2. 2. Explicitly define a protected constructor on an abstract base class.
3. 3. Selection statements (if-else and switch) should be used when the control flow depends on an object’s value; dynamic binding should be used when the control flow depends on the object’s type. This is a general OO principle. Please note that it is usually a design error to write a selection statement that queries the type of an object (keywords typeof, is).

Exception:

Using a selection statement to determine if some object implements one or more optional interfaces is a valid construct though.

4. All variants of an overloaded method shall be used for the same purpose and have similar behavior.

4.3 Use C# to describe pre-conditions post-conditions, exceptions, and class invariants.
1. 1. It shall be possible to use a reference to an object of a derived class wherever a reference to that object’s base class object is used.
2. 2. Do not modify the value of any of the operands in the implementation of an overloaded operator.
3. 3. Use a struct when value semantics are desired. More precisely, a struct should be considered for types that meet any of the following criteria:
4. � Act like primitive types.
5. � Have an instance size fewer than .16 bytes.
6. � Are immutable.
7. � Value semantics are desirable.
8. � Remember that a struct cannot be derived from.
9. 4. Allow properties to be set in any order.

Properties should be stateless with respect to other properties, i.e. there should not be an observable difference between first setting property A and then B and its reverse.

Page 16 of 21

5. Use a property rather than a method when the member is a logical data member.
6. Use a method rather than a property when this is more appropriate.

In some cases a method is better than a property:

� The operation is a conversion, such as Object.ToString.
� The operation is expensive enough that you want to communicate to the user that they should consider caching the result.
� Obtaining a property value using the get accessor would have observable side effect.
� Calling the member twice in succession produces different results.
� The order of execution is important
� The member is static but returns a value that can be changed.
� The member returns a copy of an internal array or other reference type.
� Only a set accessor would be supplied. Write-only properties tend to be confusing.
7. Do not create a constructor that does not yield a fully initialized object.
8. Always check the result of an as operation.

If you use as to obtain a certain interface reference from an object, always ensure that this operation does not return null. Failure to do so may cause a NullReferenceException at a later stage if the object did not implement that interface.

4.4 Exceptions

Name exceptions with the “Exception” suffix.

Use Pascal Casing

Consider naming exceptions using nouns or noun phrases

1. Only throw exceptions in exceptional situations.

Do not throw exceptions in situations that are normal or expected (e.g. end-of-file). Use return values or status enumerations instead. In general, try to design classes that do not throw exceptions in the normal flow of control. However, do throw exceptions that a user is not allowed to catch when a situation occurs that may indicate a design error in the way your class is used.

2. Do not throw exceptions from inside destructors.

When you call an exception from inside a destructor, the CLR will stop executing the destructor, and pass the exception to the base class destructor (if any). If there is no base class, then the destructor is discarded.

3. Only re-throw exceptions when you want to specialize the exception.

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Only catch and re-throw exceptions if you want to add additional information and/or change the type of the exception into a more specific exception. In the latter case, set the InnerException property of the new exception to the caught exception.

4. List the explicit exceptions a method or property can throw.

Describe the recoverable exceptions using the <exception> tag.

Explicit exceptions are the ones that a method or property explicitly throws from its implementation and which users are allowed to catch. Exceptions thrown by .NET framework classes and methods used by this implementation do not have to be listed here.

5. Always log that an exception is thrown.

Logging ensures that if the caller catches your exception and discards it, traces of this exception can be recovered at a later stage.

6. Allow callers to prevent exceptions by providing a method or property that returns the object’s state.

For example, consider a communication layer that will throw an InvalidOperationException when an attempt is made to call Send () when no connection is available. To allow preventing such a situation, provide a property such as Connected to allow the caller to determine if a connection is available before attempting an operation.

7. Use standard exceptions.

8. Throw informational exceptions.

When you instantiate a new exception, set its Message property to a descriptive message that will help the caller to diagnose the problem

9. Throw the most specific exception possible.

10. Do not throw an exception from inside an exception constructor.

Throwing an exception from inside an exception’s constructor will stop the construction of the exception being built, and hence, preventing the exception from getting thrown. The other exception is thrown, but this can be confusing to the user of the class or method concerned.

4.5 Delegates & Events
1. 1. Do not make assumptions on the object’s state after raising an event.

Prepare for any changes to the current object’s state while executing an event handler. The event handler may have called other methods or properties that changed the object’s state (e.g. it may have disposed objects referenced through a field).

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2. Raise events through a protected virtual method.

If a derived class wants to intercept an event, it can override such a virtual method, do its own work, and then decide whether or not to call the base class version. Since the derived class may decide not to call the base class method, ensure that it does not do any work required for the base class to function properly. Name this method OnEventName, where EventName should be replaced with the name of the event.

3. Use the sender/arguments signature for event handlers.

The goal of this recommendation is to have a consistent signature for all event handlers. In general, the event handler’s signature should look like this public delegate void MyEventHandler(object sender, EventArgs arguments)

Using the base class as the sender type allows derived classes to reuse the same event handler. The same applies to the arguments parameter. It is recommended to derive from the .NET Framework’ s EventArgs class and add your own event data. Using such a class prevents cluttering the event handler’ signature, allows extending the event data without breaking any existing users, and can accommodate multiple return values (instead of using reference fields). Moreover, all event data should be exposed through properties, because that allows for verification and preventing access to data that is not always valid in all occurrences of a certain event.

4. Implement add/remove accessors if the number of handlers for an event must be limited.

If you implement the add and remove accessors of an event, then the CLR will call those accessors when an event handler is added or removed. This allows limiting the number of allowed event handlers, or to check for certain preconditions.

Consider providing property-changed events.

Consider providing events that are raised when certain properties are changed. Such an event should be named

PropertyChanged, where Property should be replaced with the name of the property with which this event is associated.

5. Consider an interface instead of a delegate.

If you provide a method as the target for a delegate, the compiler will only ensure that the method signature matches the delegate’s signature.

This means that if you have two classes providing a delegate with the same signature and the same name, and each class has a method as a target for that delegate, it is possible to provide the method of the first class as a target for the

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delegate in the other class, even though they might not be related at all. Therefore, it is sometimes better to use interfaces. The compiler will ensure that you cannot accidentally provide a class implementing a certain interface to a method that accepts another interface that happens to have the same name.

5 Framework Specific Guidelines
5.1 Data Access
1. 1. Always use type-safe data sets. Avoid raw ADO.NET.
2. 2. Always use transactions when accessing a database.
3. 3. Always use transaction isolation level set to Serializable.
4. a. Requires management decision to use anything else.
5. 4. Do not use the Server Explorer to drop connections on windows forms, ASP.NET forms or web services. Doing so couples the presentation tier to the data tier.
6. 5. Avoid SQL Server authentication.
7. a. Use Windows authentication instead.
8. 6. Run components accessing SQL Server under separate identity from that of the calling client.
9. 7. Always warp your stored procedures in a high level, type safe class. Only that class invokes the stored procedures.
10. 8. Avoid putting any logic inside a stored procedure.
11. a. If there is an IF inside a stored procedure, you are doing something wrong.
5.2 ASP.NET and Web Services
1. 1. Avoid putting code in ASPX files of ASP.NET. All code should be in the code behind class.
2. 2. Code in code behind class of ASP.NET should call other components rather than contain direct business logic.
3. 3. In both ASP.NET pages and web services, wrap a session variables in a local property. Only that property is allowed to access the session variable, and the rest of the code uses the property, not the session variable.
4. 4. In transactional pages or web services, always store session in SQL server.
5. 5. Strive to provide interfaces for web services
6. 6. Always provide namespace and service description for web services.
7. 7. Always provide a description for web methods.

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8. When adding a web service reference, provide meaningful name for the location.
9. Always modify client-side web service wrapper class to support cookies.
a. You have no way of knowing whether the service uses Session state or not.

5.3 Serialization
1. 1. Always mark non-sealed classes as Serializable.
2. 2. Always mark un-serializable member variables as non serializable.
3. 3. Always mark delegates on a serialized class as non-serializable fields:

[Serializable]

public class MyClass

{

[field:NonSerialized]

public event MyDelegate Delegate;

}

5.4 Remoting
1. 1. Prefer administrative configuration to programmatic configuration.
2. 2. Always implement IDisposable on a single call objects.
3. 3. Always prefer TCP channel and binary format when using remoting.
4. a. Unless a firewall is present.
5. 4. Always provide a null lease for a singleton object.

public class MySingleton : MarshalByRefObject

{

public override object InitializeLifetimeService()

{

return null;

}

5. Always provide a sponsor for a client-activated object. Sponsor should return initial lease timed.

6. Always unregistered a sponsor on client application shutdown.

7. Always put remote objects in class libraries.

8. Avoid using SoapSuds.

9. Avoid hosting in IIS.

10. Avoid using uni-directional channels.

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11. Always elevate type filtering to full on both client and host to allow callbacks.

Host Config file:

</serverProviders>

</channel>

</serverProviders>

</channel>

</channels>

Client Config file:

</serverProviders>

</channel>

</channels>

DotNet First Side

KINDLY READ AND GET BACK TO ME URGENTLY.

Reminder about your invitation from Anil Kumar Reddy Perugu

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Reminder about your invitation from Anil Kumar Reddy Perugu

LinkedIn

Invitation to connect on LinkedIn

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HTTP Status Code - 410 Gone

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