Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim i As Integer
        For i = 1 To 10
            円の描画(120, 120, i * 10)
        Next
    End Sub

    Public Sub 円の描画(ByVal x As Integer, ByVal y As Integer, ByVal r As Integer)
        Dim g As Graphics
        Dim ペン As Pen
        g = Me.CreateGraphics
        ペン = New Pen(Color.Black)
        g.DrawEllipse(ペン, x - r, y - r, r * 2, r * 2)
    End Sub