帮助：窗口打开SW_SHOWMAXIMIZED时处理WM_SHOWWINDOW [英] HELP: Handling WM_SHOWWINDOW when window opened SW_SHOWMAXIMIZED

问题描述

我已经验证了当使用SW_SHOWMAXIMIZED调用ShowWindow时，WM_SHOWWINDOW处理程序OnShowWindow（）不是

。我创建了一个

虚拟MFC应用程序（doc / view，没有doc / view）并重现了这个行为。

所以，这就是我所拥有的（简化）......



没有文档/视图支持的MFC应用程序。



CMyWinApp :: InitInstance（）

{

...

pMainFrame->的ShowWindow（m_nCmdShow）;

pMainFrame-> UpdateWindow（）;

...

}



CMainFrame :: OnShowWindow（...）

{

//当m_nCmdShow == SW_SHOWMAXIMIZED时未调用!!

}



这似乎是设计行为。有谁知道为什么？在这种情况下我可以处理什么

消息来知道窗口何时显示在
屏幕上？

I've verified that the WM_SHOWWINDOW handler OnShowWindow() is not
called when ShowWindow is called with SW_SHOWMAXIMIZED. I created a
dummy MFC app (doc/view and no doc/view) and reproduced the behavior.
So, here is what I have (simplified)...

MFC app with no doc/view support.

CMyWinApp::InitInstance()
{
...
pMainFrame->ShowWindow(m_nCmdShow);
pMainFrame->UpdateWindow();
...
}

CMainFrame::OnShowWindow(...)
{
// Not called when m_nCmdShow == SW_SHOWMAXIMIZED!!
}

This seems to be the designed behavior. Does anyone know why? What
message can I handle in this case to know when the window is shown on
screen?

推荐答案

请阅读WM_SHOWWINDOW上的MSDN文档。



http://msdn.microsoft.com/en-us/library/windows/desktop/ms632645%28v=vs.85%29.aspx [< a href =http://msdn.microsoft.com/en-us/library/windows/desktop/ms632645%28v=vs.85%29.aspxtarget =_ blanktitle =New Window> ^ ]

Please read the MSDN documentation on WM_SHOWWINDOW.

http://msdn.microsoft.com/en-us/library/windows/desktop/ms632645%28v=vs.85%29.aspx[^]

The WM_SHOWWINDOW message is not sent under the following circumstances:

*  When a top-level, overlapped window is created with the WS_MAXIMIZE or WS_MINIMIZE style.
*  When the SW_SHOWNORMAL flag is specified in the call to the ShowWindow function.

我刚刚尝试使用MFC SDI应用程序，当使用 m_pMainWnd-> ShowWindow时它会调用 CMainFrame :: OnShowWindow （SW_SHOWMAXIMIZED）;

您还可以为 WM_SIZE 创建处理程序（ CMainFrame :: OnSize ）进行处理虽然会被多次调用。

I just tried this with an MFC SDI application and it does call CMainFrame::OnShowWindow when using m_pMainWnd->ShowWindow(SW_SHOWMAXIMIZED);
You could also create a handler for WM_SIZE (CMainFrame::OnSize) to do your processing although it would be called multiple times.

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