void CMyDlg::OnPaint()
{
 if (IsIconic())
 {
  CPaintDC dc(this); // device context for painting

  SendMessage(WM_ICONERASEBKGND, (WPARAM) dc.GetSafeHdc(), 0);

  // Center icon in client rectangle
  int cxIcon = GetSystemMetrics(SM_CXICON);
  int cyIcon = GetSystemMetrics(SM_CYICON);
  CRect rect;
  GetClientRect(&rect);
  int x = (rect.Width() - cxIcon + 1) / 2;
  int y = (rect.Height() - cyIcon + 1) / 2;

  // Draw the icon
  dc.DrawIcon(x, y, m_hIcon);
 }
 else
 {
  CRect rc;
  GetWindowRect(&rc);
  CDC *pDC;
  CDC memdc;
  CBitmap *olddc;
  CBitmap bitmap;
  bitmap.LoadBitmap(IDB_BITMAP1);
  pDC=this->GetDC();
  memdc.CreateCompatibleDC(pDC);
  olddc=memdc.SelectObject(&bitmap);
  pDC->BitBlt(0,0,rc.Width(),rc.Height(),&memdc,0,0,SRCCOPY);
  if(olddc)
  {
   memdc.SelectObject(olddc);
  }
  CDialog::OnPaint();
 }
}