Ajax Interview Questions and Answers Posted by Unknown on 12:19 AM

Interview Star presents new exclusive and fundamental Ajax Interview Questions and Answers

what is Ajax?

Ajax is asynchronous JavaScript and XML.it can use only those control in your page that post back to server side.it can avid UN usable control that can every time auto post back to server side.Ajax is time consuming .

ex.In your web form 5 control only you have 2 control can auto post back every time at server side. you can add that control in update panel.

What role “#&&” plays in a querysting?

# works as a fragment delimeter in a querysting. With which you can delimit history state.
While && preceeds, state information in query string.

Is there any property names “IsNavigating”?

Yes, it is available when you are managing browser history.
With this property of “IsNavigating”, you can determine if postback is occurred for navigation purpose or for some other.
Its set to true if its navigation call.

What is AjaxControl ToolKit?

AjaxControl Toolkit is an open source project built on top of ajax framework. It has more than 30 controls which are really cool and useful.

Visit this site to find out more about AjaxControlToolKit.

http://www.asp.net/(S(fu2l2uzphr2u3u45q2dnez55))/ajax/AjaxControlToolkit/Samples/

What will happen with click of browser “back” button among asynchronous requests?

By default, browser will unload the web page and and will return to previous Web page, independent of any asynchronous requests.

Tell name of all the control of Ajax?

There are 5 controls.
1. ScriptManager
2. UpdatePanel
3. UpdateProgress
4. Timer
5. ScriptManageProxy

If there are multiple update panels on the page say Upd1 and Upd2. There is a button placed in Upd1. How can you stop Upd2 to update when button placed in upd1 is clicked?

There is a property called UpdateMode which takes two values
1.Always : Default value of this property.
2.Conditional

When set to conditional, then that updatepanel's content only gets updated when control placed in that update panel does a postback. Control placed in other update panel will not affect this updatepanel.

How many types of triggers are there in update panel?

There are 2 types of triggers.
1. PostBackTrigger : It does a full postback. This is useful when any such control which placed within updatePanel but it cannot work asynchronously. Like File Upload Control.
2. AsyncPostBackTrigger :- It does partial post back asynchronously.

What is the DisplayAfter property in UpdateProgress control?

Displayafter property specifies after how many seconds the loading image needs to be displayed in ajax postback. It takes values in seconds.

Is it compulsory to have Script manager on the page when you are using any control of ajax control tool kit?

Yes. Page needs to have a script manager for ajax control tool kit controls to work.

Is it possible to use FileUpload control within the update panel?

Yes, it's possible. But we need to use Postback triggers to upload the file.

Which property needs to be set for script manager control to extend the time before throwing time out expection if no response is received from the server?

AsyncPostBackTimeout Property needs to set which gets or sets a value that indicates the time, in seconds, before asynchronous postback time out if no response is received from the server.