在画布上画圆画线画圆弧的实例

Public Class Form1

    Sub Draw(ByVal vType As Integer)
        Dim g As System.Drawing.Graphics
        Dim p As New Pen(Color.Red) ''建立一支红色的笔
        g = Me.CreateGraphics() '取得画布
        g.Clear(Color.White) '清除画布
        Select Case vType
            Case (0)
                g.DrawEllipse(p, 90, 30, 90, 90) ''画圆
            Case (1)
                g.DrawLine(p, 90, 50, 180, 100) '画线
            Case (2)
                g.DrawArc(p, 90, 30, 90, 90, 0, 250) ''画圆弧?
        End Select
    End Sub

    Private Sub btnCircle_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCircle.Click
        Draw(0)
    End Sub

    Private Sub btnLine_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnLine.Click
        Draw(1)
    End Sub

    Private Sub btnArc_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnArc.Click
        Draw(2)
    End Sub

End Class