Private Sub btn_Click(sender as Object, e as Eventargs) Handels btn.Click
    MessageBox.Show(ctype(sender,button).Name.ToString)
End Sub

Private Sub Form_Load(...) Handles Form.Load
    Addhandler btn1.Click, Addressof Berechne
    AddHandler btn2.Click, Addressof Berechne
End Sub
 
Private Sub Berechne(sender as object, e as eventargs)
    btn = ctype(sender,button)
    MessageBox.Show("der button " & btn.name & " wurde gedrückt")
End Sub