画面清除的问题

Question

使用重画……或者重载onpaint();

Answer 1

可以用  grfGraphics.Clear(Color.WhiteSmoke) 覆盖背景颜色 假设画布背景颜色 是WhiteSmoke
 
        Dim grfGraphics As Graphics = Picture1.CreateGraphics
        grfGraphics.Clear(Color.WhiteSmoke)
        grfGraphics.SmoothingMode = SmoothingMode.AntiAlias
        Dim pen2 As Pen = New Pen(Color.Blue, 1)
        pen2.DashStyle = DashStyle.Solid
        Dim fnt As Font
        fnt = New Font("Impact", 100, FontStyle.Bold)
        '画x坐标
        grfGraphics.DrawLine(pen2, Picture1.Width - 25, Picture1.Height - 25,   Picture1.Width - 1, Picture1.Height - 15)
  grfGraphics.DrawLine(pen2, Picture1.Width - 25, Picture1.Height - 5, Picture1.Width - 1, Picture1.Height - 15)
        grfGraphics.DrawLine(pen2, 0, Picture1.Height - 15, Picture1.Width - 1, Picture1.Height - 15)