void CSelRectDlg::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    {        CRgn r1, r2, r3;        bool combin;        CPaintDC dc(this);        combin = true;        CRect rect1(20, 20, 200, 200);        CRect rect2(150, 20, 330, 200);        dc.BeginPath();        dc.Ellipse(&rect1);        dc.EndPath();        r1.CreateFromPath(&dc); //创建一个圆形路径        dc.Ellipse(&rect1); //画出圆形        dc.BeginPath();        dc.Ellipse(&rect2);        dc.EndPath();        r2.CreateFromPath(&dc);        dc.Ellipse(&rect2);        CString str1;        if(r1.CombineRgn(&r1, &r2, RGN_AND) == NULLREGION) //合并重叠区            combin = false;        if(combin == true)        {            CBrush br;            br.CreateSolidBrush(RGB(128, 128, 128));            dc.FillRgn(&r1, &br);        }        CDialog::OnPaint();    }}