VB.net 電卓 (演算ボタン)

演算ボタンをまとめて書くとき
#Region "演算ボタン"
Private Sub btnEnzan_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnPlus.Click, btnMinus.Click, btnMulti.Click, btnDiv.Click

'演算子(＋、−、＊、/)のボタンを押したとき
Select Case True

Case sender Is Me.btnPlus
idx2 = 0
Case sender Is Me.btnMinus
idx2 = 1
Case sender Is Me.btnMulti
idx2 = 2
Case sender Is Me.btnDiv
idx2 = 3

End Select

以上。