Question

I have an ASP.NET DDL that looks like this when I view source:

<select name='testControl' onchange='DoCustomStuff();setTimeout('__doPostBack(\'testControl\',\'\')', 0)' id='testControl'> 

It looks like this on the .cs page:

<asp:DropDownList ID='testControl' runat='server' onchange='DoCustomStuff()' OnSelectedIndexChanged='testControl_Changed' AutoPostBack='true' /> 

Can anyone see a problem with using onchange and AutoPostBack=’true’ on a DDL like this? I ask because we have some users for whom the DoCustomStuff() doesn’t seem to be called correctly, and I’m wondering if it would be possible for the __doPostBack() to be executed before DoCustomStuff() completes its work.

Answer 1

Try to attach postback reference manually like that :

Page.ClientScript.RegisterClientScriptBlock(   typeof(_Default),    'PageScripts',    string.Format('function DoCustomStuff() { /* Your Code Here */ {0} }', Page.ClientScript.GetPostBackEventReference(testControl, string.Empty)) );  testControl.Attributes['onchange'] =  'DoCustomStuff();'; 

this gives you the postback client side reference :

Page.ClientScript.GetPostBackEventReference(testControl, string.Empty))