Question

VB按下鼠标可画

由鼠标事在窗体上画图，按下鼠标可画图，双击可清除画图。
补充完整

dim paintstart as boolean
private sub form_load()
drawwidth=2
forecolor=vbgreen
end sub
private sb form_mousedown(button as integer,shift as integer,_x as single,
y as single)
()
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

最好解析一下

Answer 1

在MouseDown事件里的代码： PaintStart = True 解析：鼠标按下时把全局变量PaintStart标记为True，表示可以开始画东西了。

在MouseUp事件里的代码：PaintStart = False 解析：鼠标松开时吧全局变量PaintStart标记为Flase，表示要停止画东西了。