The difference between Postback and CallBack ?

I know that Postback referring to the action users click a button to submit the form data.

In what situations do we say mention thecallbackaction?

(I found that there is a property Page.IsCallBack)

Regards,

Ricky

Hi there,

The difference between a callback and postback is that, as with a postback, a callback does not refresh the currently viewed page (i.e. does not redraw the page). You can think of it as a quick trip back to get some data etc. For example if there were two drop down boxes, the second dependant on the value of the first, when a user selects a value of a the first, rather then posting the whole page, doing some server side calculations and returning a new whole page to the client, a callback can enable you to only go fetch the required data. Obviously from this, View State is not updated with a callback (it's the same instance of the page just updated!!!).

Hope this helps.

Tom thats a good answer to the original posters question. So am I right in thinking callback are the core of the whole AJAX craze. I'm learning ajax at the moment, not ajax.net for just the regular ajax fundamentals and what you've sais about only fetching required date seems to ring a bell.

Also can callaback be implemented without the use of the .net ajax framework?

Hi,

Altough similar in end results to what can be achieved with AJAX (but limited compared to ajax) the callback functionality is not part of its framework and is a feature of just .NET 2.0 (other options avaialble with 1.1). Try the following article for more information it puts the difference between callback functionalty and AJAX into context.

http://www.geekpedia.com/tutorial155_ASP.NET-2.0-Script-CallBack-(Ajax-like).html

Thanks

i dont know it may help you or not... just check out this

This feature allows you to programmatically call server-side methods through client-side JavaScript code without the need for posting back the page.

http://dotnetjunkies.com/Article/E80EC96F-1C32-4855-85AE-9E30EECF13D7.dcik

with good sample

Thanks a lot, Tom.

Ricky.