ASP.Net Interview Questions - I

1. What is ASP.Net?

It is a framework developed by Microsoft on which we can develop new generation web sites using web forms(aspx), MVC, HTML, Javascript, CSS etc. Its successor of Microsoft Active Server Pages(ASP). Currently there is ASP.NET 4.0, which is used to develop web sites. There are various page extensions provided by Microsoft that are being used for web site development. Eg: aspx, asmx, ascx, ashx, cs, vb, html, xml etc.

2. What’s the use of Response.Output.Write()?
 We can write formatted output  using Response.Output.Write().

3. In which event of page cycle is the ViewState available?
   After the Init() and before the Page_Load().

4. What is the difference between Server.Transfer and Response.Redirect?  

In Server.Transfer page processing transfers from one page to the other page without making a round-trip back to the client’s browser.  This provides a faster response with a little less overhead on the server.  The clients url history list or current url Server does not update in case of Server.Transfer.

Response.Redirect is used to redirect the user’s browser to another page or site.  It performs trip back to the client where the client’s browser is redirected to the new page.  The user’s browser history list is updated to reflect the new address.

5. From which base class all Web Forms are inherited?

Page class. 

6. What are the different validators in ASP.NET?

1.    Required field Validator 
2.    Range  Validator
3.    Compare Validator
4.    Custom Validator
5.    Regular expression Validator
6.    Summary Validator

7. Which validator control you use if you need to make sure the values in two different controls matched?

Compare Validator control.

8. What is ViewState?

ViewState is used to retain the state of server-side objects between page post backs.

9. Where the viewstate is stored after the page postback?

ViewState is stored in a hidden field on the page at client side.  ViewState is transported to the client and back to the server, and is not stored on the server or any other external source.

10. How long the items in ViewState exists?

They exist for the life of the current page.

11. What are the different Session state management options available in ASP.NET?

1.    In-Process
2.   Out-of-Process.

In-Process stores the session in memory on the web server.

Out-of-Process Session state management stores data in an external server.  The external server may be either a SQL Server or a State Server.  All objects stored in session are required to be serializable for Out-of-Process state management.

12. How you can add an event handler?

 Using the Attributes property of server side control.

e.g.

btnSubmit.Attributes.Add("onMouseOver","JavascriptCode();")

13. What is caching?

Caching is a technique used to increase performance by keeping frequently accessed data or files in memory. The request for a cached file/data will be accessed from cache instead of actual location of that file.

14. What are the different types of caching?
ASP.NET has 3 kinds of caching :

   

1. Output Caching,
2. Fragment Caching,
3. Data Caching.

15. Which type if caching will be used if we want to cache the portion of a page instead of whole page?

Fragment Caching: It caches the portion of the page generated by the request. For that, we can create user controls with the below code:

<%@ OutputCache Duration="120" VaryByParam="CategoryID;SelectedID"%>

16. List the events in page life cycle.

1) Page_PreInit
2) Page_Init
3) Page_InitComplete
4) Page_PreLoad
5) Page_Load
6) Page_LoadComplete
7) Page_PreRender
8)Render

17. Can we have a web application running without web.Config file?

  Yes

18. Is it possible to create web application with both webforms and mvc?

Yes. We have to include below mvc assembly references in the web forms application to create hybrid application.

System.Web.Mvc  System.Web.Razor  System.ComponentModel.DataAnnotation

19. Can we add code files of different languages in App_Code folder?

  No. The code files must be in same language to be kept in App_code folder.

20. What is Protected Configuration?

It is a feature used to secure connection string information.

21. Write code to send e-mail from an ASP.NET application?

1 2 3 4 5 6 7

MailMessage mailMess = new MailMessage ();         mailMess.From = "abc@gmail.com";         mailMess.To = "xyz@gmail.com";         mailMess.Subject = "Test email";         mailMess.Body = "Hi This is a test mail.";         SmtpMail.SmtpServer = "localhost";         SmtpMail.Send (mailMess);

MailMessage and SmtpMail are classes defined System.Web.Mail namespace.

 22. How can we prevent browser from caching an ASPX page?

  We can SetNoStore on HttpCachePolicy object exposed by the Response object’s Cache property:

Response.Cache.SetNoStore ();  Response.Write (DateTime.Now.ToLongTimeString ());

23. What is the good practice to implement validations in aspx page?
Client-side validation is the best way to validate data of a web page. It reduces the network traffic and saves server resources.

24. What are the event handlers that we can have in Global.asax file?

Application Events: Application_Start , Application_End, Application_AcquireRequestState, Application_AuthenticateRequest, Application_AuthorizeRequest, Application_BeginRequest, Application_Disposed,  Application_EndRequest, Application_Error, Application_PostRequestHandlerExecute, Application_PreRequestHandlerExecute,
Application_PreSendRequestContent, Application_PreSendRequestHeaders, Application_ReleaseRequestState, Application_ResolveRequestCache, Application_UpdateRequestCache

Session Events: Session_Start,Session_End

25. Which protocol is used to call a Web service?
HTTP Protocol

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