怎么判断按键

Question

void CMFDlg::OnEnUpdateEdit1()
{
SumWater(); //自定义函数，计算的
}

我想判断 按键，如果是空格键就清空edit

要怎么判断呢？

谢谢

Answer 1

可以再CMFDlg类中重写PreTranslateMessage虚函数，在里面过滤WM_KEYDOWN消息，判断空格键是否按下，比如这样：
BOOL CMFDlg::PreTranslateMessage(MSG* pMsg)
{
   if(WM_KEYDOWN == pMsg->message && VK_SPACE == pMsg->wParam)
   {
        SetDlgItemText(IDC_EDIT1, _T(""));
        return TRUE;
   }
   return CDialog::PreTranslateMessage(pMsg);
}

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Visual C++ enthusiast, like network programming and driver development. At present is being engaged in the WinCE/Windows Mobile platform embedded development.

Answer 2

void CMFDlg::OnEnUpdateEdit1()  
{ 
       BOOL CMFDlg::PreTranslateMessage(MSG* pMsg)//错误1
       {//错误2
              if(WM_KEYDOWN == pMsg->message && VK_SPACE == pMsg->wParam)
              {
                     SetDlgItemText(IDC_EDIT1, _T(""));
                     return TRUE;
              }
                     return CDialog::PreTranslateMessage(pMsg);
              }
       SumWater();
}

是这样吗？

总是有这两个错误

1 IntelliSense:  不能在成员函数 "CMFCDlg::PreTranslateMessage" 的类外部重新声明该函数 c:\Users\hui\Documents\Visual Studio 2013\Projects\MFCsum\MFCsum\MFCDlg.cpp 198 19 MFCsum

2 IntelliSense:  应输入“;” c:\Users\hui\Documents\Visual Studio 2013\Projects\MFCsum\MFCsum\MFCDlg.cpp 199 2 MFCsum

没弄明白

Answer 3

不是的，是在CMFCDlg类中添加虚函数PreTranslateMessage。

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Visual C++ enthusiast, like network programming and driver development. At present is being engaged in the WinCE/Windows Mobile platform embedded development.