getpixel 取色

HWND hwnd = ::FindWindow(NULL,"《天龙八部OL》");
    CRect rect;
    CString strTmp;
    if (hwnd != NULL)
    {
        ::SetWindowPos(hwnd,HWND_TOP,0,0,0,0,SWP_NOSIZE|SWP_NOMOVE|SWP_SHOWWINDOW);
        ::GetWindowRect(hwnd,&rect);
        
        ::SetForegroundWindow(hwnd);
        
        HDC hdc=::GetDC(NULL);
        if (hdc==NULL)
        {
            MessageBox("getwindowDC");
        }
        ::InvalidateRect(hwnd,NULL,1);

        COLORREF color1=GetPixel(hdc,rect.left+250,rect.top+235);
        COLORREF color2=GetPixel(hdc,rect.left+265,rect.top+235);
        COLORREF color3=GetPixel(hdc,rect.left+260,rect.top+230);
        COLORREF color4=GetPixel(hdc,rect.left+260,rect.top+240);
        COLORREF color5=GetPixel(hdc,rect.left+200,rect.top+200);
        COLORREF color6=GetPixel(hdc,rect.left+180,rect.top+235);
        strTmp.Format("%X,%X,%X,%X,%x,%x",(DWORD)color1,(DWORD)color2,(DWORD)color3,(DWORD)color4,(DWORD)color5,(DWORD)color6);
    
        m_edtString=m_edtString+"
"+strTmp;
        UpdateData(FALSE);
        SetCursorPos(rect.left+260,rect.top+235);
        mouse_event(MOUSEEVENTF_LEFTDOWN,0,0,0,0);
        //mouse_event(MOUSEEVENTF_LEFTUP,0,0,0,0);                //不抬起不会进入。

        ::ReleaseDC(hwnd,hdc);