I have posted - Determining the Control that Caused a PostBack a long back.
However, In ASP.NET, there's no property anywhere that can tell you which control caused the postback. The ID of the posting control, however, is not difficult to find.
The answer to this all jargon is – One Client side Hidden field named __EVENTTARGET and one JS fucntion named – __doPostBack()
But thanks to
The following code shows how to determine whether the user clicked a menu item or posted back to the server through another control:
ScriptManager sm = ScriptManager.GetCurrent(this);
string ctlID = sm.AsyncPostBackSourceElementID;
Control c = this.FindControl(ctlID);
if (c == null)
return (c.ID == "Menu1");
Hope this help.
Thanks & Regards,
Arun Manglick Senior Tech Lead