Enable Disable Controls During AJAX Postback

Most of us use Microsoft AJAX Toolkit and Controls but we don’t know when Ajax Request starts and when it ends. Sometimes we need to do enabling and disabling controls during postback. This can be done using the code below.


var _employee=null;
var _department=null;
var _subdepartment=null;

function pageLoad(sender, args){
// Register start request and end request event handler Sys.WebForms.PageRequestManager.getInstance().add_beginRequest(beginRequest);
Sys.WebForms.PageRequestManager.getInstance().add_endRequest(endRequest); }

// fired when ajax request starts
function beginRequest(sender, args){
_ employee = $get('ctl00_ContentPlaceHolder1_ddlemployee);
_ department = $get('ctl00_ContentPlaceHolder1_ddldepartment);
_ subdepartment = $get('ctl00_ContentPlaceHolder1_ddlsubdepartment);
_ employee.disabled=true;
_ department.disabled=true;
_ subdepartment.disabled=true; }

// fired when ajax request ends
function endRequest(sender, args) {
_ employee.disabled=false;
_ department.disabled=false;
_ subdepartment.disabled=false;
}


Here I have added two event handlers to request manager class instance. Event will be fired when request starts or ends. Isn’t it easy? :)

Ref : http://mattberseth.com/blog/