ASP.Net

 

1. Order of events in an asp.net page? Control Execution Lifecycle?

Phase	What a control needs to do	Method or event to override
Initialize	Initialize settings needed during the lifetime of the incoming Web request.	Init event (OnInit method)
Load view state	At the end of this phase, the ViewState property of a control is automatically populated as described in Maintaining State in a Control. A control can override the default implementation of the LoadViewState method to customize state restoration.	LoadViewState method
Process postback data	Process incoming form data and update properties accordingly.	LoadPostData method (if IPostBackDataHandler is implemented)
Load	Perform actions common to all requests, such as setting up a database query. At this point, server controls in the tree are created and initialized, the state is restored, and form controls reflect client-side data.	Load event (OnLoad method)
Send postback change notifications	Raise change events in response to state changes between the current and previous postbacks.	RaisePostDataChangedEvent method (if IPostBackDataHandler is implemented)
Handle postback events	Handle the client-side event that caused the postback and raise appropriate events on the server.	RaisePostBackEvent method(if IPostBackEventHandler is implemented)
Prerender	Perform any updates before the output is rendered. Any changes made to the state of the control in the prerender phase can be saved, while changes made in the rendering phase are lost.	PreRender event (OnPreRender method)
Save state	The ViewState property of a control is automatically persisted to a string object after this stage. This string object is sent to the client and back as a hidden variable. For improving efficiency, a control can override the SaveViewState method to modify the ViewState property.	SaveViewState method
Render	Generate output to be rendered to the client.	Render method
Dispose	Perform any final cleanup before the control is torn down. References to expensive resources such as database connections must be released in this phase.	Dispose method
Unload	Perform any final cleanup before the control is torn down. Control authors generally perform cleanup in Dispose and do not handle this event.	UnLoad event (On UnLoad method)

 

2. What are server controls?

ASP.NET server controls are components that run on the server and encapsulate user-interface and other related functionality. They are used in ASP.NET pages and in ASP.NET code-behind classes.

3. What is the difference between Web User Control and Web Custom Control?

Web custom controls are compiled code, which makes them easier to use but more difficult to create; Web custom controls must be authored in code. Once you have created the control, however, you can add it to the Toolbox and display it in a visual designer with full Properties window support and all the other design-time features of ASP.NET server controls. In addition, you can install a single copy of the Web custom control in the global assembly cache and share it between applications, which makes maintenance easier.

Web user controls are easy to make, but they can be less convenient to use in advanced scenarios. You develop Web user controls almost exactly the same way that you develop Web Forms pages. Like Web Forms, user controls can be created in the visual designer, they can be written with code separated from the HTML, and they can handle execution events. However, because Web user controls are compiled dynamically at run time they cannot be added to the Toolbox, and they are represented by a simple placeholder glyph when added to a page. This makes Web user controls harder to use if you are accustomed to full Visual Studio .NET design-time support, including the Properties window and Design view previews. Also, the only way to share the user control between applications is to put a separate copy in each application, which takes more maintenance if you make changes to the control.

Web user controls	Web custom controls
Easier to create	Harder to create
Limited support for consumers who use a visual design tool	Full visual design tool support for consumers
A separate copy of the control is required in each application	Only a single copy of the control is required, in the global assembly cache
Cannot be added to the Toolbox in Visual Studio	Can be added to the Toolbox in Visual Studio
Good for static layout	Good for dynamic layout

 

4. Difference between ASP Session and ASP.NET Session?

Asp.net session supports cookie less session & it can span across multiple servers.

5. What method do you use to explicitly kill a users session?

Abandon()

6. What is State Management in .Net and how many ways are there to maintain a state in .Net? What is view state?

Web pages are recreated each time the page is posted to the server. In traditional Web programming, this would ordinarily mean that all information associated with the page and the controls on the page would be lost with each round trip.
To overcome this inherent limitation of traditional Web programming, the ASP.NET page framework includes various options to help you preserve changes — that is, for managing state. The page framework includes a facility called view state that automatically preserves property values of the page and all the controls on it between round trips.
However, you will probably also have application-specific values that you want to preserve. To do so, you can use one of the state management options.

Client-Based State Management Options:
View State
Hidden Form Fields
Cookies
Query Strings

Server-Based State Management Options
Application State
Session State
Database Support

7. What are the disadvantages of view state / what are the benefits?

Automatic view-state management is a feature of server controls that enables them to repopulate their property values on a round trip (without you having to write any code). This feature does impact performance, however, since a server control's view state is passed to and from the server in a hidden form field. You should be aware of when view state helps you and when it hinders your page's performance.

8. Explain the differences between Server-side and Client-side code?

Server side code will process at server side & it will send the result to client. Client side code (javascript) will execute only at client side.

9. What is Role-Based security?

A role is a named set of principals that have the same privileges with respect to security (such as a teller or a manager). A principal can be a member of one or more roles. Therefore, applications can use role membership to determine whether a principal is authorized to perform a requested action.

10. What are the different authentication modes in the .NET environment?

Authentication mode are Windows,Forms,Passport,None.

11. What are validator? Name the Validation controls in asp.net?

A set of server controls included with ASP.NET that test user input in HTML and Web server controls for programmer-defined requirements. Validation controls perform input checking in server code. If the user is working with a browser that supports DHTML, the validation controls can also perform validation ("EnableClientScript" property set to true/false) using client script.

The following validation controls are available in asp.net:
RequiredFieldValidator Control, CompareValidator Control, RangeValidator Control, RegularExpressionValidator Control, CustomValidator Control, ValidationSummary Control.

12. Asp.net - How to find last error which occurred?

Server.GetLastError();

13. How to do Caching in ASP?

<%@ OutputCache Duration="60" VaryByParam="None" %>

14. What is the use of web.config?

ASP.NET configuration files are XML-based text files--each named web.config--that can appear in any directory on an ASP.NET Web application server. Each web.config file applies configuration settings to the directory it is located in and to all virtual child directories beneath it.

15. What is the use of sessionstate tag in the web.config file?

Session state features can be configured via the <sessionState> section in a web.config file. To double the default timeout of 20 minutes, you can add the following to the web.config file of an application:
<sessionState timeout="40" />

16. What are the different modes for the sessionstates in the web.config file?

Off	Indicates that session state is not enabled.
Inproc	Indicates that session state is stored locally.
StateServer	Indicates that session state is stored on a remote server.
SQLServer	Indicates that session state is stored on the SQL Server.

 

17. What is smart navigation?

When a page is requested by an Internet Explorer 5 browser, or later, smart navigation enhances the user's experience of the page by performing the following:

• eliminating the flash caused by navigation.
• persisting the scroll position when moving from page to page.
• persisting element focus between navigations.
• retaining only the last page state in the browser's history.

Smart navigation is best used with ASP.NET pages that require frequent postbacks but with visual content that does not change dramatically on return. Consider this carefully when deciding whether to set this property to true.
Set the SmartNavigation attribute to true in the @ Page directive in the .aspx file. When the page is requested, the dynamically generated class sets this property.

18. Is it possible for me to change my aspx file extension to some other name?

Yes.
Open IIS->Default Website -> Properties
Select HomeDirectory tab
Click on configuration button
Click on add. Enter aspnet_isapi details (C:\WINDOWS\Microsoft.NET\Framework\v1.0.3705\aspnet_isapi.dll   |  GET,HEAD,POST,DEBUG)

Open machine.config(C:\WINDOWS\Microsoft.NET\Framework\v1.0.3705\CONFIG) & add new extension under <httpHandlers> tag
<add verb="*" path="*.but" type="System.Web.UI.PageHandlerFactory"/>

19. What is Remoting?

The process of communication between different operating system processes, regardless of whether they are on the same computer. The .NET remoting system is an architecture designed to simplify communication between objects living in different application domains, whether on the same computer or not, and between different contexts, whether in the same application domain or not.

20. Difference between web services & remoting?

	ASP.NET Web Services	.NET Remoting
Protocol	Can be accessed only over HTTP	Can be accessed over any protocol (including TCP, HTTP, SMTP and so on)
State Management	Web services work in a stateless environment	Provide support for both stateful and stateless environments through Singleton and SingleCall objects
Type System	Web services support only the datatypes defined in the XSD type system, limiting the number of objects that can be serialized.	Using binary communication, .NET Remoting can provide support for rich type system
Interoperability	Web services support interoperability across platforms, and are ideal for heterogeneous environments.	.NET remoting requires the client be built using .NET, enforcing homogenous environment.
Reliability	Highly reliable due to the fact that Web services are always hosted in IIS	Can also take advantage of IIS for fault isolation. If IIS is not used, application needs to provide plumbing for ensuring the reliability of the application.
Extensibility	Provides extensibility by allowing us to intercept the SOAP messages during the serialization and deserialization stages.	Very extensible by allowing us to customize the different components of the .NET remoting framework.
Ease-of-Programming	Easy-to-create and deploy.	Complex to program.