1. As you can disable other controls, use following method :
GetDlgItem(IDC_EDIT)->EnableWindow(FALSE);
OR :
m_edit_ctrl.EnableWindow(FALSE);
and with ' TRUE ', to enable that.
When disable an Edit Control the containing text becomes grayed and the caret (text cursor) will be disappeared (no 'copy' capability).
2. You can use SetReadOnly function (It becomes read_only and the
containing text remains Black and caret exists (with 'copy' capability) :
m_edit_ctrl.SetReadOnly(TRUE);