Wednesday, June 25, 2008

ASP.NET Interview Questions Part - 1

Hi,
Here are some of the interview questions that may help you. I have collected it from different sites and documented here. ASP.NET and C# interview questions,

1. Explain page life cycle?
Answer: While excuting the page, it will go under the fallowing steps(or fires the events) which collectivly known as Page Life cycle.

Page_Init -- Page Initialization
LoadViewState -- View State Loading
LoadPostData -- Postback data processing
Page_Load -- Page Loading
RaisePostDataChangedEvent -- PostBack Change Notification
RaisePostBackEvent -- PostBack Event Handling
Page_PreRender -- Page Pre Rendering Phase
SaveViewState -- View State Saving
Page_Render -- Page Rendering
Page_UnLoad -- Page Unloading

2. What is cross page posting in ASP.NET2.0 ?
Answer
: When we have to post data from one page to another in application we used server.transfer method but in this the URL remains the same but in cross page posting there is little different there is normal post back is done but in target page we can access values of server control in the source page.This is quite simple we have to only set the PostBackUrl property of Button,LinkButton or imagebutton which specifies the target page.In target page we can access the PreviousPage property.And we have to use the @PreviousPageType directive.We can access control of PreviousPage by using the findcontrol method.When we set the PostBackURL property ASP.NET framework bind the HTML and Javascript function automatically.

3. What is Finalizer in .NET define Dispose and Finalize ?
Answer
: We can say that Finalizer are the methods that's helps in cleanp the code that is executed before object is garbage collected .The process is called finalization . There are two methods of finalizer Dispose and Finalize .There is little diffrenet between two of this method .When we call Dispose method is realse all the resources hold by an object as well as all the resorces hold by the parent object.When we call Dispose method it clean managed as well as unmanaged resources.Finalize methd also cleans resources but finalize call dispose clears only the unmanged resources because in finalization the garbase collecter clears all the object hold by managed code so finalization fails to prevent thos one of methd is used that is: GC.SuppressFinalize.
 
4. What is Satellite Assemblies ?
Answer
: Satellite assemblies are often used to deploy language-specific resources for an application. These language-specific assemblies work in side-by-side execution because the application has a separate product ID for each language and installs satellite assemblies in a language-specific subdirectory for each language. When uninstalling, the application removes only the satellite assemblies associated with a given language and .NET Framework version. No core .NET Framework files are removed unless the last language for that .NET Framework version is being removed. For example, English and Japanese editions of the .NET Framework version 1.1 share the same core files. The Japanese .NET Framework version 1.1 adds satellite assemblies with localized resources in a \ja subdirectory. An application that supports the .NET Framework version 1.1, regardless of its language, always uses the same core runtime files.

5. Automatic Memory Management ?
Answer: Automatic Memory Management: From a programmer's perspective, this is probably the single biggest benefit of the .NET Framework. No, I'm not kidding. Every project I've worked on in my long career of DOS and Windows development has suffered at some point from memory management issues. Proper memory management is hard. Even very good programmers have difficulty with it. It's entirely too easy for a small mistake to cause a program to chew up memory and crash, sometimes bringing the operating system to a screeching halt in the process.Programmers understand that they're responsible for releasing any memory that they allocate, but they're not very good at actually doing it. In addition, functions that allocate memory as a side effect abound in the Windows API and in the C runtime library. It's nearly impossible for a programmer to know all of the rules. Even when the programmer follows the rules, a small memory leak in a support library can cause big problems if called enough.The .NET Framework solves the memory management problems by implementing a garbage collector that can keep track of allocated memory references and release the memory when it is no longer referenced. A large part of what makes this possible is the blazing speed of today's processors. When you're running a 2 GHz machine, it's easy to spare a few cycles for memory management. Not that the garbage collector takes a huge number of cycles--it's incredibly efficient.The garbage collector isn't perfect and it doesn't solve the problem of mis-managing other scarce resources (file handles, for example), but it relieves programmers from having to worry about a huge source of bugs that trips almost everybody up in other programming environments.On balance, automatic memory management is a huge win in almost every situation.

6. What is view state and use of it?
Answer:The current property settings of an ASPNET page and those of any ASPNET server controls contained within the page. ASPNET can detect when a form is requested for the first time versus when the form is posted (sent to the server), which allows you to program accordingly.

7. What do you mean by authentication and authorization?
Answer:Authentication is the process of validating a user on the credentials (username and password) and authorization performs after authentication. After Authentication a user will be verified for performing the various tasks, It access is limited it is known as authorization.

8. What's the difference between Page.RegisterClientScriptBlock and Page.RegisterStartupScript?
Answer
:RegisterClientScriptBlock is for returning blocks of client-side script containing functions. RegisterStartupScript is for returning blocks of client-script not packaged in functions-in other words, code that's to execute when the page is loaded. The latter positions script blocks near the end of the document so elements on the page that the script interacts are loaded before the script runs.