ASP.NET: Find which control caused a postback

Summary: Pass the page to the function and the control that caused the postback will be returned from the function

Public Function GetPostBackControl(ByVal page As System.Web.UI.Page) As System.Web.UI.Control
' Find which control caused the postback
Dim control As Control = Nothing
Dim ctrlname As String = page.Request.Params("__EVENTTARGET")
If Not (ctrlname Is Nothing) AndAlso Not (ctrlname = String.Empty) Then
control = page.FindControl(ctrlname)
Else
Dim ctrlStr As String = String.Empty
Dim c As Control = Nothing
For Each ctl As String In page.Request.Form
If ctl.EndsWith(".x") OrElse ctl.EndsWith(".y") Then
ctrlStr = ctl.Substring(0, ctl.Length - 2)
c = page.FindControl(ctrlStr)
Else
c = page.FindControl(ctl)
End If
If TypeOf c Is System.Web.UI.WebControls.Button OrElse TypeOf c Is System.Web.UI.WebControls.ImageButton Then
control = c
' break
End If
Next
End If
Return control
End Function

This Hack is part of the ASP.NET Hacks collection

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