关于模态/非模态对话框不响应菜单的UPDATE_COMMAND_UI消息

对于模态非模态对话框默认是不响应菜单的UPDATE_COMMAND_UI消息的，需要增加对WM_INITMENUPOPUP消息的处理以后，才可以响应UPDATE_COMMAND_UI。

void CXXXDlg::OnInitMenuPopup(CMenu* pPopupMenu, UINT nIndex, BOOL bSysMenu)  
{  
     CDialog::OnInitMenuPopup(pPopupMenu, nIndex, bSysMenu);  

    // TODO: Add your message handler code here  

     if(!bSysMenu && pPopupMenu)  
     {  
          CCmdUI cmdUI;  
          cmdUI.m_pOther = NULL;  
          cmdUI.m_pMenu = pPopupMenu;  
          cmdUI.m_pSubMenu = NULL;  

          UINT count = pPopupMenu->GetMenuItemCount();  
          cmdUI.m_nIndexMax = count;  
          for(UINT i=0; i<count; i++)  
          {  
               UINT nID = pPopupMenu->GetMenuItemID(i);  
               if(-1 == nID || 0 == nID)  
               {  
                    continue;  
               }  
                   cmdUI.m_nID = nID;  
                   cmdUI.m_nIndex = i;  
                   cmdUI.DoUpdate(this, FALSE);  
              }  
     }   
}   

转处：http://blog.csdn.net/visualeleven/article/details/5513648
参考：https://support.microsoft.com/en-us/help/242577/you-cannot-change-the-state-of-a-menu-item-from-its-command-user-inter