GDI+ 双缓冲

BOOL CXXXDlg::OnEraseBkgnd(CDC *pDC)

{

    CRect  rect;

    this->GetClientRect(rect);



    if(!m_pBkImage)                                                          //定义的一个成员变量

    {

        m_pBkImage = new Image(_T("main_frame.png"));

    }



    Bitmap bmp(rect.right, rect.bottom);



    Graphics bmpGraphics(&bmp);

    bmpGraphics.SetSmoothingMode(SmoothingModeAntiAlias);

    bmpGraphics.DrawImage(m_pBkImage, 0, 0, rect.Width(), rect.Height());    //Drawing on bitmap





    Graphics graphics(pDC->m_hDC);                                           //Drawing on DC



    CachedBitmap cachedBmp(&bmp,&graphics);

    graphics.DrawCachedBitmap(&cachedBmp, 0, m_iCaptionH);



    graphics.ReleaseHDC(pDC->m_hDC);



    return TRUE;

}