Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        Dim G As Graphics

        G = PictureBox1.CreateGraphics()

        '移動坐標原點(那么原點下就變成了(20,pictruebox1.height\2))

        G.TranslateTransform(20, PictureBox1.Height \ 2)

        '繪制X軸與Y軸

        'Y軸

        G.DrawLine(Pens.Black, 20, -PictureBox1.Height \ 2, 20, PictureBox1.Height \ 2)

        'X軸

        G.DrawLine(Pens.Black, -20, 0, PictureBox1.Width, 0)

        '正弦函數(shù)

        Dim X, Y As Double

        For X = 0 To 400 Step 0.002

            Y = 60 * Math.Sin(2 * 3.1415926 * X / 200)

            G.DrawLine(Pens.Blue, CInt(X), 0, CInt(X), CInt(Y))

            Application.DoEvents()

        Next

        For X = 0 To 400 Step 0.002

            Y = 60 * Math.Sin(2 * 3.1415926 * X / 200)

            G.DrawLine(Pens.Red, CInt(X), 0, CInt(X), CInt(Y))

            Application.DoEvents()

        Next

    End Sub