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

  Dim G As Graphics

G = PictureBox1.CreateGraphics()

  '移动坐标原点(那么原点下就变成了(20,pictruebox1.height\2))

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

  '绘制X轴与Y轴

  'Y轴

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

  'X轴

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

'正弦函数

  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