How to Identify which event cause Postback using VB.Net?

Protected Function GetControlThatCausedPostBack(ByVal page As Page) As Control
Dim control As Control = Nothing
Dim ctrlname As String = page.Request.Params.[Get]("__EVENTTARGET")
If ctrlname IsNot Nothing AndAlso ctrlname <> String.Empty Then
control = page.FindControl(ctrlname)
Else
For Each ctl As String In page.Request.Form
Dim c As Control = page.FindControl(ctl)
If TypeOf c Is System.Web.UI.WebControls.Button OrElse TypeOf c Is System.Web.UI.WebControls.ImageButton Then
control = c
Exit For
End If
Next
End If
Return control
End Function

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Dim str As Control
str = GetControlThatCausedPostBack(Me)