怎样才能在我enter键弹起来后才执行？请看！！

BOOL CHarmonyExpView::PreTranslateMessage(MSG* pMsg) 
{
    if (pMsg->message==WM_KEYDOWN && pMsg->wParam==VK_RETURN) //截取回车键
{ keybd_event( VK_SPACE,
                      0x45,                     
KEYEVENTF_EXTENDEDKEY | 0,
                      0 );  
         if(pMsg->message==WM_KEYUP && pMsg->wParam==VK_RETURN )
 {
    
// Simulate a key press    
keybd_event( VK_SPACE,
                      0x45,                     
KEYEVENTF_EXTENDEDKEY | 0,
                      0 );       
     
// Simulate a key release
 keybd_event( VK_SPACE,                      
          0x45,
                      KEYEVENTF_EXTENDEDKEY | KEYEVENTF_KEYUP,
                      0);  }

}

return CFormView::PreTranslateMessage(pMsg);
}
我想在我的 回车键弹起后才发送空格键，可是我发现我只要按下回车后，它就不停的发送回车。怎样改？？