Multi-line CEditView

I'm having a terrible time getting text to wrap in
a CEditView window.  I'm not certain if the underlying
CEdit is single-line or multi-line; it's acting like
single-line.  I tried overriding PreCreateWindow as
follows:

BOOL MyEditView::PreCreateWindow(CREATESTRUCT& cs)
{
      m_dwDefaultStyle = dwStyleDefault | ES_MULTILINE;
      return CCtrlView::PreCreateWindow(cs);
}

but that didn't work (and actually when I commented out
the " |ES_MULTILINE " part of the first line and looked
at m_dwDefaultStyle , it appeared that ES_MULTILINE was
set without my intervention).
There doesn't seem to be any member that tells me explicitly
whether I've succeeded in making the control multi-line.

I've tried calling CEdit::SetMargins(), CEdit::FmtLines(),
and CEdit::SetRect() on the control, and no matter
what I do, the text *just* *won't* *wrap*.

If it matters, the CEditView window is a pane of
a splitter window.