如何捕捉控件中的KEYDOWN事件

[meteorkin]

必须我如何知道我在某个textbox中按下了del键
然后什么事也不做

[ddszhan]

自己做一个继承自标准CEdit类的类,在其中处理KEYDOWN事件
然后可以用控件子类化的方法
m_myEdit.SubclassDlgItem(IDC_EDIT1,this);
来使用,当然也可以直接使用
CMyEdit m_myEdit;
m_myEdit.Create(......);

[sorryIdonotknow]

up

[qwexing]

1。Add a member variable to your CWinApp-derived class to hold the handle to the dialog box for which you want to trap the messages. You need to know the handle because ProcessMessageFilter is receiving messages for the entire application, while you only want a small selection of those messages:

SCRIBBLE.H

<Inside CScribbleApp class>

public:
HWND m_hwndDialog;

SCRIBBLE.CPP

<Inside CScribbleApp::InitInstance>

m_hwndDialog = NULL;
NOTE: Because this message filter applies to the entire application, there may be a performance hit when you use this method.


2。Override CWinApp::ProcessMessageFilter in your CWinApp-derived class. CWinApp::ProcessMessageFilter is a virtual function of CWinApp, so all you need to do is put a declaration in the header file and an implementation in the source file.

SCRIBBLE.H

public:
virtual BOOL ProcessMessageFilter(int code, LPMSG lpMsg);

SCRIBBLE.CPP

BOOL CScribbleApp::ProcessMessageFilter(int code, LPMSG lpMsg)
{
// Check to make sure CPenWidthsDlg is up
if (m_hwndDialog != NULL)
{
if ((lpMsg->hwnd == m_hwndDialog) ||
::IsChild(m_hwndDialog, lpMsg->hwnd))
// Use ::IsChild to get messages that may be going
// to the dialog's controls. In the case of
// WM_KEYDOWN this is required.
{
if (lpMsg->message == WM_KEYDOWN)
TRACE("Got WM_KEYDOWN\n");
}
}
// Default processing of the message.
return CWinApp::ProcessMessageFilter(code, lpMsg);
}
For more information on overriding ProcessMessageFilter, please see the MFC online Help.


3。Add initialization code for the dialog handle member variable in our OnInitDialog for the desired dialog box. You also have to add exit code to reset the member variable after the dialog box closes:

PENDLG.H

protected:
virtual BOOL OnInitDialog();
afx_msg void OnDestroy();

PENDLG.CPP

<Add to Message Map>
ON_WM_DESTROY()

BOOL CPenWidthsDlg::OnInitDialog()
{
CDialog::OnInitDialog();

// Use AfxGetApp() to get pointer to CWinApp-derived
// object; then cast the pointer to our type and assign
((CScribbleApp *)AfxGetApp())->m_hwndDialog = m_hWnd;

return TRUE; // Return TRUE
// unless you set the focus to a control.
}

void CPenWidthsDlg::OnDestroy()
{
CDialog::OnDestroy();

// Use AfxGetApp() to get pointer to CWinApp-derived
// object; then cast the pointer to our type and assign
((CScribbleApp *)AfxGetApp())->m_hwndDialog = NULL;

}

[pubutan]

if(pMsg->message==WM_KEYDOWN)
{
UINT ID=GetFocus()->GetDlgCtrlID();
if(ID==IDC_MESSAGE_LIST)
{

}
}

[bluestone]

窗口的键盘消息在TranslateMessage中被处理了，所以在你的对话框中得不到这个消息，你可以这么做，覆盖对话框的PreTranslateMessage，他是在窗口处理键盘消息之前调用的，在它里面你可以接收到键盘消息，试试吧~~：）

函数原型：

virtual BOOL PreTranslateMessage( MSG* pMsg );

[bluestone]

如果不明白，继续说说PreTranslateMessage中的写法，例如：

BOOL 控件所在的对话框::PreTranslateMessage(MSG* pMsg)
{
CWnd * hwnd = GetDlgItem (控件ID);
if(pMsg->message == WM_KEYDOWN && pMsg->hwnd == hwnd)
{
switch(pMsg->wParam)
{
case VK_DELETE:
你的东东：）；
return TRUE;
}
}

return CDialog::PreTranslateMessage(pMsg);
}