ASP.net - Interview questions and answers for exerienced.
What is ASP.NET?
ASP.NET is a specification developed by Microsoft to create dynamic Web applications, Web sites, and Web services. It is a part of .NET Framework. You can create ASP.NET applications in most of the .NET compatible languages, such as Visual Basic, C#, and J#. The ASP.NET compiles the Web pages and provides much better performance than scripting languages, such as VBScript. The Web Forms support to create powerful forms-based Web pages. You can use ASP.NET Web server controls to create interactive Web applications. With the help of Web server controls, you can easily create a Web application.
Describe state management in ASP.NET.
State management is a technique to manage a state of an object on different request.
The HTTP protocol is the fundamental protocol of the World Wide Web. HTTP is a stateless protocol means every request is from new user with respect to web server. HTTP protocol does not provide you with any method of determining whether any two requests are made by the same person.
Maintaining state is important in any web application. There are two types of state management system in ASP.NET.
- Client-side state management
- Server-side state management
In which event are the controls fully loaded?
Page load event guarantees that all controls are fully loaded. Controls are also accessed in Page_Init events but you will see that view state is not fully loaded during this event
What is the lifespan for items stored in ViewState?
The items stored in ViewState live until the lifetime of the current page expires including the postbacks to the same page.
How can we identify that the Page is Post Back?
Page object has an "IsPostBack" property, which can be checked to know that is the page posted back.
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.
What are the different validators in ASP.NET?
Required field Validator
Range Validator
Compare Validator
Custom Validator
Regular expression Validator
Summary Validator
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”%>
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
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.DataAnnotations
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.
What are the different Session state management options available in ASP.NET?
In-Process
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.
How you can add an event handler?
Using the Attributes property of server side control.
e.g.
btnSubmit.Attributes.Add(“onMouseOver”,”JavascriptCode();”)
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.
What are the different types of caching?
Output Caching,
Fragment Caching,
Data Caching.
Write code to send e-mail from an ASP.NET application?
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);
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
What is a "Virtual Directory"?
Virtual directories are aliases for directory paths on the server. It allows moving files on the disk between different folders, drives or even servers without changing the structure of web pages. It avoids typing an extremely long URL each time to access an ASP page.
What is Query string collection?
This collection stores any values that are provided in the URL. This can be generated by three methods:
By clicking on an anchor tag
By sending a form to the server by the GET method
Through user-typed HTTP address
It allows you to extract data sent to the server using a GET request.
What are the attributes of the tags? What are their functions?
The two attributes are ACTION and METHOD
The ACTION gives the name of the ASP file that should be opened next by which this file can access the information given in the form The METHOD determines which of the two ways (POST or GET) the browser can send the information to the server
What are the methods in Session Object?
The Session Object has only one method, which is Abandon. It destroys all the objects stored in a Session Object and releases the server resources they occupied.
What is a Form collection?
The Form collection holds the values of the form elements submitted with the POST method. This is the only way to generate a Form collection.
What are the ASP Scripting Objects?
The Dictionary object, the FileSystemObject object, TextStream object.
Explain role based security ?
Role Based Security used to implement security based on roles assigned to user groups in the organization.
Then we can allow or deny users based on their role in the organization. Windows defines several built-in groups, including Administrators, Users, and Guests.
<AUTHORIZATION>< authorization >
< allow roles=”Domain_Name\Administrators” / > < !– Allow Administrators in domain. — >
< deny users=”*” / > < !– Deny anyone else. — >
< /authorization >
What is Cross Page Posting?
When we click submit button on a web page, the page post the data to the same page. The technique in which we post the data to different pages is called Cross Page posting. This can be achieved by setting POSTBACKURL property of the button that causes the postback. Findcontrol method of PreviousPage can be used to get the posted values on the page to which the page has been posted.
