如何在基于 MFC 对话框的应用程序中为复选框捕获 MouseMove 事件？

Question

My application is a VC6 MFC dialog based application with multiple property pages.

I have to capture a mousemove event over a control, for example Checkbox.

How can I capture the mousemove events over a checkbox in MFC?

Answer 1

A checkbox is a button control (eg. CWnd). Derive your own class from CCheckBox and handle the OnMouseMove event.

Per request...assuming a class derived from CButton...

BEGIN_MESSAGE_MAP(CMyCheckBox, CButton)
    ON_WM_MOUSEMOVE()
END_MESSAGE_MAP()


void CMyCheckBox::OnMouseMove(UINT nFlags, CPoint point)
    {
    // TODO: Add your message handler code here and/or call default

    CButton::OnMouseMove(nFlags, point);
    }

Answer 2

Thanks for your replies.. I found a way to get the mousemove event for my app.

WM_SETCURSOR windows message gets the mouse move. It returns the Cwnd pointer for a control and the dialog.

Find my code below.

BOOL CMyDialog::OnSetCursor(CWnd* pWnd, UINT nHitTest, UINT message)
{
CWnd* pWndtooltip = GetDlgItem(IDC_STATIC_TOOLTIP); 

if (pWnd != this)
{
    if  (IDC_SN_START_ON == pWnd->GetDlgCtrlID())
        pWndtooltip->ShowWindow(SW_SHOW);

}
else
    pWndtooltip->ShowWindow(SW_HIDE);   

SetCursor(AfxGetApp()->LoadStandardCursor(IDC_ARROW));


return true;

}

Answer 3

I found in @raj's OnSetCursor() code, that the associated Member variable for IDC_STATIC_TOOLTIP is that variable to which you assign the desired tool tip text. For example, if the associated variable is m_strToolTip, assign the desired text to display during the hovering event as follows:

m_strToolTip.Format("%s", "Tool tip text goes here");

I also found that UpdateData() was required upon entry into the event handler and UpdateData(FALSE) was required before the return. The SetCursor() call seems to have no effect when commented.

Answer 4

You can also override CDialog::PreTranslateMessage :

BOOL CSomeDlg::PreTranslateMessage(MSG* pMsg)
{
  if (pMsg->message == WM_MOUSEMOVE && pMsg->hwnd == m_checkBox->m_hWnd)
  {
    ...
  }

  return CDialog::PreTranslateMessage(pMsg);
}