1。 你的代码在vc6上出错：
/////////////////////////////////////////////////////////////////////////////
// The WndProc for all CWnd's and derived classes
LRESULT CALLBACK
AfxWndProc(HWND hWnd, UINT nMsg, WPARAM wParam, LPARAM lParam)
{
// special message which identifies the window as using AfxWndProc
if (nMsg == WM_QUERYAFXWNDPROC)
return 1;
// all other messages route through message map
CWnd* pWnd = CWnd::FromHandlePermanent(hWnd);
ASSERT(pWnd != NULL);
ASSERT(pWnd->m_hWnd == hWnd);
if (pWnd == NULL || pWnd->m_hWnd != hWnd)
return ::DefWindowProc(hWnd, nMsg, wParam, lParam);
return AfxCallWndProc(pWnd, hWnd, nMsg, wParam, lParam);
}
2。因为：
HWND CWnd::Detach()
{
HWND hWnd = m_hWnd;
if (hWnd != NULL)
{
CHandleMap* pMap = afxMapHWND(); // don't create if not exist
if (pMap != NULL)
pMap->RemoveHandle(m_hWnd);
m_hWnd = NULL;
}
#ifndef _AFX_NO_OCC_SUPPORT
m_pCtrlSite = NULL;
#endif
return hWnd;
}
