CDialog处理VK_ESCAPE的时机：

最新推荐文章于 2024-05-06 22:34:16 发布

原创最新推荐文章于 2024-05-06 22:34:16 发布 · 1.7k 阅读

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#dialog #processing #null #command #filter

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本文介绍了一个对话框类BOOLCDialog中的PreTranslateMessage方法实现细节。该方法通过过滤特定消息来改进对话框的行为，例如处理Esc键在多行编辑框中的行为，并允许工具提示消息过滤。此外，还介绍了如何避免在帮助模式下翻译对话框消息。

BOOL CDialog::PreTranslateMessage(MSG* pMsg)
{
   // for modeless processing (or modal)
   ASSERT(m_hWnd != NULL);

   // allow tooltip messages to be filtered
   if (CWnd::PreTranslateMessage(pMsg))
       return TRUE;

   // don't translate dialog messages when in Shift+F1 help mode
   CFrameWnd* pFrameWnd = GetTopLevelFrame();
   if (pFrameWnd != NULL && pFrameWnd->m_bHelpMode)
       return FALSE;

   // fix around for VK_ESCAPE in a multiline Edit that is on a Dialog
   // that doesn't have a cancel or the cancel is disabled.
   if (pMsg->message == WM_KEYDOWN &&
       (pMsg->wParam == VK_ESCAPE || pMsg->wParam == VK_CANCEL) &&
       (::GetWindowLong(pMsg->hwnd, GWL_STYLE) & ES_MULTILINE) &&
       _AfxCompareClassName(pMsg->hwnd, _T("Edit")))
   {
       HWND hItem = ::GetDlgItem(m_hWnd, IDCANCEL);
       if (hItem == NULL || ::IsWindowEnabled(hItem))
       {
           SendMessage(WM_COMMAND, IDCANCEL, 0);
           return TRUE;
       }
   }
   // filter both messages to dialog and from children
   return PreTranslateInput(pMsg);
}