激活后台窗口

SetWindowPos(&wndTopMost, 0, 0, 0, 0, SWP_NOSIZE|SWP_NOMOVE); 
SetWindowPos(&wndNoTopMost, 0, 0, 0, 0, SWP_NOSIZE|SWP_NOMOVE); 
HWND hCurWnd = NULL; 
DWORD lMyID; 
DWORD lCurID; 
hCurWnd = ::GetForegroundWindow(); 
lMyID = ::GetCurrentThreadId(); 
lCurID = ::GetWindowThreadProcessId(hCurWnd, NULL); 
::AttachThreadInput(lMyID, lCurID, TRUE); 
SetForegroundWindow(); 
::AttachThreadInput(lMyID, lCurID, FALSE);