关于VB橡皮擦功能

[soft2buy]

请教各位高手:

我用VB6.0 做了一个form,做成了全透明模式.我在上面画了很多的线条,form的背景图是一张有各种颜色的图片.
现在我想开发橡皮擦功能,参考了网上VB做橡皮擦的解决办法,都是建议使用背景色来画线来实现擦除的目的;而我这种情况是无法使用的,因为如果用背景色，就会在背景图上画出背景色的线条.请问有什么好的解决办法吗?

[Tiger_Zhao]

通过 DrawMode 控制绘图方式。

Option Explicit

Private bOnDrag As Boolean
Private X1 As Long
Private Y1 As Long
Private X2 As Long
Private Y2 As Long

Private Sub Form_Load()
    Me.ScaleMode = vbPixels
    Me.AutoRedraw = True
    Me.Line (50, 50)-(ScaleWidth - 50, ScaleHeight - 50), vbYellow, BF
    Me.FillStyle = vbFSSolid
    Me.FillColor = vbRed
    Me.Circle (100, 100), 80, vbRed
End Sub

Private Sub Form_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)
    If Button = vbLeftButton Then
        X1 = X
        Y1 = Y
        X2 = X
        Y2 = Y
        Me.DrawMode = vbNotXorPen
        Me.Line (X1, Y1)-(X2, Y2)
        bOnDrag = True
    End If
End Sub

Private Sub Form_MouseMove(Button As Integer, Shift As Integer, X As Single, Y As Single)
    If bOnDrag Then
        Me.Line (X1, Y1)-(X2, Y2)
        X2 = X
        Y2 = Y
        Me.Line (X1, Y1)-(X2, Y2)
    End If
End Sub

Private Sub Form_MouseUp(Button As Integer, Shift As Integer, X As Single, Y As Single)
    If (Button = vbLeftButton) And bOnDrag Then
        bOnDrag = False
        Me.Line (X1, Y1)-(X2, Y2)
        Me.DrawMode = vbCopyPen
        Me.Line (X1, Y1)-(X2, Y2)
    End If
End Sub

[cdcjk]

学习一下

[FngLng]

楼上的代码就可以，应该是截一个图，然后再动态擦除。

[我是一道光_]

其实大范围的可以 使用清屏

就是用一个矩阵，进行颜色覆盖

[qiu5208]

复制一张背景图存到内存,

擦除时
用bitblt函数把背景图再涂上,不 就是橡皮擦了.

[贝隆]

学习

[Tiger_Zhao]

用背景图的一小部分 PaintPicture。