MFC改变窗口背景颜色

class CMainWindow : public CFrameWnd
{
}

void CMainWindow::OnPaint ()
 {
   CPaintDC dc (this);
     
   CRect rect;
   GetClientRect (&rect);
   dc.FillSolidRect(&rect, RGB(255, 255, 255));  
 dc.DrawText (_T ("Hello,MFC"), -1, &rect,
   DT_SINGLELINE | DT_CENTER | DT_VCENTER);
 }class CMainWindow : public CFrameWnd
{
}

void