什么是invalidate,更新方法做在VC ++ [英] what is invalidate,update methods do in VC++

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问题描述

我对c ++中的窗口函数有点怀疑。
什么是invalidate() function do?
它发送什么消息?当我们需要调用这个?还有什么是update() function?
invalidaterect()工作类似于invalidate() function? >

感谢

解决方案

CWnd :: Invalidate() 一个窗口的整个客户区,表示该区域已过期,应重新绘制。通常在需要重绘的控件上调用此方法。 CWnd :: InvalidateRect() 仅使窗口的一部分失效。



使用 Invalidate WM_PAINT 消息将发布[不严格true;请参阅评论]到消息队列,并在将来的某个时间处理。 CWnd :: UpdateWindow() 发送(相对于帖子) WM_PAINT 消息,使无效区域立即重绘。



真的,这一切都在文档中。


i have small doubt regarding the window functions in c++. what exactly "invalidate()" function do? what message does it sends?when we need to call this? also what is "update()" function? is "invalidaterect()" works similar to "invalidate()" function?.

Thanks

解决方案

CWnd::Invalidate() invalidates the entire client area of a window, which indicates that the area is out of date, and should be repainted. You would typically call this on a control that needs to be redrawn. CWnd::InvalidateRect() invalidates only part of the window.

With the Invalidate functions, the WM_PAINT message will posted [not strictly true; see the comments] to the message queue and handled at some point in the future. CWnd::UpdateWindow() sends (as opposed to posts) a WM_PAINT message, causing the invalidated regions to be redrawn immediately.

Really, this is all in the docs.

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