求救：改一个鼠标画多条直线的代码～～
给大家发两段代码：
都是只能画一条直线～～
Imports System
Imports System.Drawing
Imports System.Drawing.Drawing2D
Public Class Line
Public WithEvents pctbox As PictureBox
Dim linePen As Pen
Dim startPoint As Point
Dim endPoint As Point
Dim endOfPoint As New Point
Dim isMouseDown As Boolean = False
Dim isFirstMove As Boolean = True
Private Sub pctbox_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles pctbox.MouseDown
isMouseDown = True
startPoint.X = e.X
startPoint.Y = e.Y
End Sub
Private Sub pctbox_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles pctbox.MouseMove
If isMouseDown Then
Dim bmp As New Bitmap(pctbox.ClientSize.Width, pctbox.ClientSize.Height)
endPoint.X = e.X
endPoint.Y = e.Y
Dim g As Graphics = Graphics.FromImage(bmp)
g.DrawLine(Pens.Blue, startPoint, endPoint)
pctbox.Image = bmp
End If
End Sub
Private Sub pctbox_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles pctbox.MouseUp
isMouseDown = False
End Sub
End Class
Imports System
Imports System.Drawing
Imports System.Drawing.Drawing2D
Public Class Line
Public WithEvents pctbox As PictureBox
Dim startPoint As Point
Dim endPoint As Point
Dim endOfPoint As New Point
Dim isMouseDown As Boolean = False
Dim isFirstMove As Boolean = True
Private Sub pctbox_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles pctbox.MouseDown
isMouseDown = True
startPoint.X = e.X
startPoint.Y = e.Y
End Sub
Private Sub pctbox_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles pctbox.MouseMove
Dim bmp As New Bitmap(pctbox.ClientSize.Width, pctbox.ClientSize.Height)
Dim mygraphics As Graphics = Graphics.FromImage(bmp)
If isMouseDown Then
If isFirstMove Then
isFirstMove = False
endPoint.X = e.X
endPoint.Y = e.Y
mygraphics.DrawLine(Pens.Red, startPoint, endPoint)
pctbox.Image = bmp
Else
endOfPoint.X = e.X
endOfPoint.Y = e.Y
mygraphics.DrawLine(Pens.Blue, startPoint, endPoint)
mygraphics.DrawLine(Pens.Black, startPoint, endOfPoint)
pctbox.Image = bmp
End If
End If
End Sub
Private Sub pctbox_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles pctbox.MouseUp
isMouseDown = False
End Sub
End Class
只能画一条直线，当画第二条直线时，第一条就消失了～～～
谁能帮我？
------解决方案--------------------
http://blog.csdn.net/wzuomin/archive/2006/12/13/1441007.aspx
