AJAX Client Side Event Life Cycle

1.      Page Request

2.      Init

3.      Load

·         initializeRequest

·         beignRequest

·         pageLoading

·         pageLoaded

4.         Load

·          endRequest

5.      unLoad

 Interview Question links :

Customize exception behavior when UpdatePanel throws an error :

1. Set AllowCustomErrorsRedirect = false on ScriptManager control to disable Custom Errors redirection.

2. Handle OnAsyncPostBackError event on ScriptManager control to change script error message and perform other tasks required on error.

What does UpdateMode =Always mean in UpdatePanel control ?

UpdateMode=Always in UpdatePanel control means all contents of updatepanel is refreshed on all kinds of page postback i.e. Control in any other update panel is postedback or control in page outside updatepanel is postedback

What is default value of UpdateMode property of ASP.NET UpdatePanel control ?

Default value of UpdateMode property of ASP.NET UpdatePanel control is Always

What are values of UpdateMode property of ASP.NET UpdatePanel control ?

There are two values of UpdateMode property of ASP.NET UpdatePanel control :

1. Always

2. Conditional

What is ASP.NET UpdatePanel  control?

ASP.NET UpdatePanel  control enables sections of a page to be partially rendered without a postback.

What is partial page update or refresh ?

Refresh selected parts of the page without postback instead of refreshing the whole page with a postback.

How to identify which control caused asynchronous postback ?

One can use AsyncPostBackSourceElementID  property of Script Manager. AsyncPostBackSourceElementID  gives the ID of the control that caused the asynchronous postback.

How to identify Async Postback in Page Load event ?

Async Postback is identified using IsInAsyncPostBack  property of Script Manger i.e. ScriptManager.IsInAsyncPostBack