1、解决CMainFrame::PreTranslateMessage执行2次的问题，原因是因为没有return TRUE造成的。由此可见，如果不return，会继续执行CMDIFrameWndEx::PreTranslateMessage，造成2次执行发生；

2、SetWindowText无效问题未解决；

SATHelper/SATHelper/ChildFrm.cpp

@@ -123,10 +123,11 @@ int CChildFrame::OnCreate(LPCREATESTRUCT lpCreateStruct)
 	return 0;
 }
 
-
+/*
 void CChildFrame::ActivateFrame(int nCmdShow)
 {
 	// TODO: 在此添加专用代码和/或调用基类
 	nCmdShow = SW_MAXIMIZE;
 	CMDIChildWndEx::ActivateFrame(nCmdShow);
 }
+*/

SATHelper/SATHelper/ChildFrm.h

@@ -48,5 +48,5 @@ protected:
 public:
 	virtual BOOL Create(LPCTSTR lpszClassName, LPCTSTR lpszWindowName, DWORD dwStyle = WS_CHILD | WS_VISIBLE | WS_OVERLAPPEDWINDOW, const RECT& rect = rectDefault, CMDIFrameWnd* pParentWnd = NULL, CCreateContext* pContext = NULL);
 	afx_msg int OnCreate(LPCREATESTRUCT lpCreateStruct);
-	virtual void ActivateFrame(int nCmdShow = -1);
+	//virtual void ActivateFrame(int nCmdShow = -1);
 };

SATHelper/SATHelper/MainFrm.cpp

@@ -281,7 +281,7 @@ int CMainFrame::OnCreate(LPCREATESTRUCT lpCreateStruct)
 	context.m_pCurrentDoc = m_pDoc;
 	context.m_pNewViewClass = RUNTIME_CLASS(CUB530View);
 	context.m_pNewDocTemplate = m_pDoc->GetDocTemplate();
-	if (m_pUB530View->LoadFrame(DLG_UB530VIEW, WS_MAXIMIZE | WS_OVERLAPPEDWINDOW /*WS_CHILDWINDOW*/, this, &context))
+	if (m_pUB530View->LoadFrame(DLG_UB530VIEW, WS_MAXIMIZE | WS_CHILDWINDOW, this, &context))
 	{
 		//m_pUB530View->ShowWindow(SW_SHOWMAXIMIZED);
 		m_pUB530View->InitialUpdateFrame(context.m_pCurrentDoc, FALSE);
@@ -312,7 +312,7 @@ int CMainFrame::OnCreate(LPCREATESTRUCT lpCreateStruct)
 	context2.m_pNewViewClass = RUNTIME_CLASS(CDeviceView);
 	context2.m_pNewDocTemplate = m_pDoc->GetDocTemplate();
 	// 说明：DLG_DEVICEMANAGER对话框的Style属性必须设置成Child才能LoadFrame成功;
-	if (m_pDeviceView->LoadFrame(DLG_DEVICEMANAGER, WS_MAXIMIZE | WS_CHILDWINDOW| WS_OVERLAPPEDWINDOW, this, &context2))
+	if (m_pDeviceView->LoadFrame(DLG_DEVICEMANAGER, WS_MAXIMIZE | WS_CHILDWINDOW, this, &context2))
 	{
 		//m_pDeviceView->ShowWindow(SW_SHOWMAXIMIZED);
 		m_pDeviceView->InitialUpdateFrame(NULL, FALSE);
@@ -686,9 +686,8 @@ BOOL CMainFrame::PreTranslateMessage(MSG* pMsg)
 	static BOOL bTopWnd = FALSE;
 	if (pMsg->message == WM_KEYDOWN)
 	{
-		switch (pMsg->wParam)
+		if (pMsg->wParam == VK_F3)
 		{
-		case VK_F3:
 			if (bTopWnd == FALSE)
 			{
 				SetWindowPos(&wndTopMost, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE);//窗口置顶
@@ -699,10 +698,11 @@ BOOL CMainFrame::PreTranslateMessage(MSG* pMsg)
 				SetWindowPos(&wndNoTopMost, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE);//取消窗口置顶	
 				SetWindowText(_T("视频采集卡-取消前置（请按F3取消或开启前置）"));
 			}
+
 			bTopWnd = !bTopWnd;
-			break;
-		default:
-			break;
+
+			// 必须退出,否则执行2次;
+			return TRUE;
 		}
 	}