how to track minimize, maximize events

[zspirit]

From an old post here

To track minimize / maximize events, you should handle WM_WINDOWPOSCHANGED message.
I would not worry about covering / uncovering of your window. Why? What if it is only partially covered? What if the top window is transparent?

I tried it but it didn't help.

void CMainFrame::OnWindowPosChanged(WINDOWPOS* lpwndpos)
{
	CFrameWnd::OnWindowPosChanged(lpwndpos);

	// TODO: Add your message handler code here
	if (lpwndpos->flags & SWP_SHOWWINDOW)
		AfxMessageBox(_T("Show"));
	else if (lpwndpos->flags & SWP_HIDEWINDOW)
		AfxMessageBox(_T("Hide"));
	
}

The control nevers come in this function, only at start time and exit time. I know one way is to check them in WM_SIZE but is that the only way? I just need to catch the events when window is maximized and restored.

[zspirit]

I am checking for the window state in OnSize() but the problem is that when I call ShowWindow() inside OnSize() it causes a flicker for a second when applicatoin starts. I want to remove that.

What I am doing is if user minimize application, it should hide, when user maximized it from system tray it should show up again. What is the best place to do that so it does not cause flicker! Thanks.

[Pravin Kumar]

Hello,

Maximizing / minimizing window can be done only by using buttons on the toolbar or by toolbar menu. One can check for the corresponding messages for the window concerned and take appropriate actions.

Whether window is being maximized / minimized can be known if we store the previous window state. If you modify the PreTranslateMessage function to some thing as shown below, you can trap the maximizing event in a simplified way.

BOOL CMainFrame::PreTranslateMessage(MSG* pMsg) 
{
	// TODO: Add your specialized code here and/or call the base class
	static int State = 0;
	BOOL Flag = CFrameWnd::PreTranslateMessage(pMsg);
	if ((State == SW_SHOWMAXIMIZED) != IsZoomed())
		// Window is getting zoomed
		...
		State = SW_SHOWMAXIMIZED;
	return Flag;
}

Regards,
Pravin.