Top ASP.NET interview questions


Posted by Pawan kumar in Interview Questions | asp.net on Monday, 11 May 2015 (Views: 451)

Tags: Top ASP.NET interview questions ASP.NET interview questions Top 50 ASP.Net Interview Questions & Answers

Question 1.    Describe the role of inetinfo.exe, aspnet_isapi.dll andaspnet_wp.exe in the page loading process.
Ans. inetinfo.exe is theMicrosoft IIS server running, handling ASP.NET requests among other things.When an ASP.NET request is received (usually a file with .aspx extension),the ISAPI filter aspnet_isapi.dll takes care of it by passing the request tothe actual worker process aspnet_wp.exe. 
 
Question 2.    What’s the difference between Response.Write() andResponse.Output.Write()?
Ans. The latter one allows you to write formattedoutput. 
 
Question 3.    What methods are fired during the page load?
Ans. Init() - when the pageis instantiated, Load() - when the page is loaded into server memory,PreRender() - the brief moment before the page is displayed to the user asHTML, Unload() - when page finishes loading. 
 
Question 4.    Where does the Web page belong in the .NET Framework class hierarchy?
Ans. System.Web.UI.Page 
 
Question 5.    Where do you store the information about the user’s locale?
Ans. System.Web.UI.Page.Culture 
 
Question 6.    What’s the difference between Codebehind="MyCode.aspx.cs" andSrc="MyCode.aspx.cs"?
Ans. CodeBehind is relevant to Visual Studio.NET only. 
 
Question 7.    What’s a bubbled event?
Ans. When you have a complex control, like DataGrid, writing an event processing routine for each object (cell, button, row, etc.) is quite tedious. The controls can bubble up their eventhandlers, allowing the main DataGrid event handler to take care of its constituents. 
 
Question 8.    Suppose you want a certain ASP.NET function executed on MouseOver overa certain button. Where do you add an event handler?
Ans. It’s the Attributesproperty, the Add function inside that property. So btnSubmit.Attributes.Add("onMouseOver","someClientCode();") 
 
Question 9.    What data type does the RangeValidator control support?
Ans. Integer,String and Date.
 
Question 10.    Explain the differences between Server-side and Client-side code?
Ans.  Server-side code runs on the server. Client-side code runs in the clients’ browser.
 
Question 11.    What type of code (server or client) is found in a Code-Behind class?
Ans. Server-side code.
 
Question 12.    Should validation (did the user enter a real date) occur server-side or client-side? Why?
Ans. Client-side. This reduces an additional request to the server to validate the users input.
 
Question 13.    What does the "EnableViewState" property do? Why would I want it on or off?
Ans.  It enables the viewstate on the page. It allows the page to save the users input on a form.
 
Question 14.    What is the difference between Server.Transfer and Response.Redirect? Why would I choose one over the other?
Ans. Server.Transfer is used to post a form to another page. Response.Redirect is used to redirect the user to another page or site.
 
Question 15.    Can you give an example of what might be best suited to place in the Application_Start and Session_Start subroutines?  
Ans. This is where you can set the specific variables for the Application and Session objects.
 
Question 16.    If I’m developing an application that must accommodate multiple security levels though secure login and my ASP.NET web application is spanned across three web-servers (using round-robin load balancing) what would be the best approach to maintain login-in state for the users?
Ans. Maintain the login state security through a database.
 
Question 17.    Can you explain what inheritance is and an example of when you might use it?
Ans. When you want to inherit (use the functionality of) another class. Base Class Employee. A Manager class could be derived from the Employee base class.
 
Question 18.    Whats an assembly?
Ans.  Assemblies are the building blocks of the .NET framework. Overview of assemblies from MSDN
 
Question 19.    Describe the difference between inline and code behind.
Ans. Inline code written along side the html in a page. Code-behind is code written in a separate file and referenced by the .aspx page.
 
Question 20.    Explain what a diffgram is, and a good use for one?
Ans. The DiffGram is one of the two XML formats that you can use to render DataSet object contents to XML. For reading database data to an XML file to be sent to a Web Service.
 
Question 21.    Whats MSIL, and why should my developers need an appreciation of it if at all?
Ans. MSIL is the Microsoft Intermediate Language. All .NET compatible languages will get converted to MSIL.
 
Question 22.    Which method do you invoke on the DataAdapter control to load your generated dataset with data?
Ans. The .Fill() method
 
Question 23.    Can you edit data in the Repeater control?  
Ans. No, it just reads the information from its data source
 
Question 24.    Which template must you provide, in order to display data in a Repeater control?
Ans. ItemTemplate
 
Question 25.    How can you provide an alternating color scheme in a Repeater control?
Ans. Use the AlternatingItemTemplate
 
Question 26.    What property must you set, and what method must you call in your code, in order to bind the data from some data source to the Repeater control?
Ans. You must set the DataSource property and call the DataBind method.
 
Question 27.    What base class do all Web Forms inherit from?
Ans.  The Page class.
 
Question 28.    Name two properties common in every validation control?
Ans. ControlToValidate property and Text property.
 
Question 29.    What tags do you need to add within the asp:datagrid tags to bind columns manually?
Ans. Set AutoGenerateColumns Property to false on the datagrid tag
 
Question 30.    What is the transport protocol you use to call a Web service?
Ans. SOAP is the preferred protocol.