下面程序是由鼠标事件在窗体上画图，如果按下鼠标可以画图，双击窗体则可以清除所画图形。补充完整下面的程序。首先在窗体层定义如下变量： Dim PaintStart As Boolean 编写如下事件过程： Private Sub Form_Load() DrawWidth=2 ForeColor=vbGreen End Sub Private Sub Form_MouseDown(Button As Integer，Shift As Integer，X AS Single，Y AS Single) PaintStart=True End Sub Private Sub Form_MouseMove(Button As Integer，Shift As Integer，X As Single，Y As Single) If PaintStart Then PSet(X，Y) End If End Sub Private Sub Form_MouseUp(Button As Integer，Shift As Integer，X As Single，Y As Single) End Sub Private Sub Form_DblClick() Cls End Sub