One of the most important features of the ASP.NET environment is the ability to declare controls that run on the server, and post back to the same page. Remember the days of classic ASP? We would create a form which would accept the user's input, and then we would most probably have to create another page that would accept all those inputs, either through HTTP GET or POST, and perform some kind of validation, display and action. Sometimes, even a third page was necessary to perform our actions. This wasted a lot of time and complicated things when you had to make a change. But of course, this is not necessary any more with ASP.NET. There is no need to create second pages that accept the inputs of the first, process them and so on. Form fields and other controls can be declared to run on the server, and the server simply posts the page back to itself and performs all the validation, display and actions. Our life as web developers has become a million times better. But how exactly is this done?
When a control is declared to run on the server, a VIEWSTATE is created which remembers the ID of that control, and the method to call when an action is performed. For example, let's say we input this HTML on a page:
This is a very simple page. We declare only one web control, a linkbutton, to run on the server, with an ID of Test and we assign a method called Test_Click to run when the link is clicked on the page. The linkbutton has to be wrapped inside a form that runs on the server as well. We save the above as an ASPX page and then we browse to it. The HTML that gets created looks like this:
- eventTarget: the control doing the submission
- eventArgument: any additional information for the event
Here is the code behind statements which are used to get the target name and also the argument is passed from the do postback call.
The above article is take from this link
All and any comments / bugs / suggestions are welcomed!