Question

When typing into a CRichEditCtrl, EN_CHANGE messages are generated. However MSDN says:

Rich Edit: Supported in Microsoft Rich
Edit 1.0 and later. To receive
EN_CHANGE notifications, specify
ENM_CHANGE in the mask sent with the
EM_SETEVENTMASK message. For
information about the compatibility of
rich edit versions with the various
system versions, see About Rich Edit
Controls.

The EN_CHANGE notification is not sent
when the ES_MULTILINE style is used
and the text is sent through
WM_SETTEXT.

I have several dialogs using a multi-line rich edit control, actually my custom CMyRichEdit class. That class automatically performs analysis when the text changes, but in the important case where the dialog is initially populated, no notification is seen.

The point is to avoid having to change our code-base more than absolutely necessary – the new control is being dropped in to replace existing ones. Chasing down every instance where getDlgItem(IDC_EDIT)->SetWindowText is used, or where DDX_Text(pDX, IDC_EDIT, m_strEdit) automatically links a string contents with the control, would mean a lot of trawling through code and re-testing everything altered.

Is there an easy way? Can MyRichEdit catch its own WM_SETTEXT messages?

Answer 1

ON_MESSAGE(WM_SETTEXT, OnSetText)

// fires every time someone calls SetWindowText
LRESULT MyRichEditCtrl::OnSetText(WPARAM wParam, LPARAM lParam)
{
    return CWnd::Default();
}