BOOL CDisplayBmpBackGroundDlg::OnEraseBkgnd(CDC   *pDC)

{

 CRect rect;

 GetClientRect(&rect);

 CBitmap m_pBmp;

 BITMAP bm;

 CDC dcMem;

 m_pBmp.LoadBitmap(IDB_BITMAP1);

 m_pBmp.GetBitmap(&bm);//得到位图尺寸

 dcMem.CreateCompatibleDC(pDC);

 CBitmap* pOldBitmap = dcMem.SelectObject(&m_pBmp);

  pDC->SetStretchBltMode(COLORONCOLOR);//这个模式不设置的话会导致图片严重失真

 pDC->StretchBlt(0,0,rect.Width() ,rect.Height(),

  &dcMem,0,0,bm.bmWidth,bm.bmHeight,SRCCOPY);

 dcMem.SelectObject(pOldBitmap);

 return TRUE;

}