从外部程序读取了错误的像素颜色，需要偏移吗？

Question

I'm trying to read a pixel from an external program and then get its RGB colors. This works flawlessly whenever I find the location with the mouse and extract the pixel colors. However when I try to do it from a console program, the RBG colors comes back.. differently than what I expected.

I believe it could be an offset missing, so whenever I find the location using my mouse it's using my screens pixel, and whenever I activate the external program using the function below it will take the pixel locations from that window handle.

It could also be something about it being a game, and it's getting drawn differently, any tips? If I try to get the pixel colors from notepad it works.

[DllImport("user32.dll")] static extern bool SetForegroundWindow(IntPtr hWnd);
public static void Activate(string processName = "CookieGame")
{
     var processes = Process.GetProcessesByName(processName);
     var process = processes.FirstOrDefault();
     if (process != null)
     {
       SetForegroundWindow(process.MainWindowHandle);
     }
}

I use the following function for extracting pixel colors from a location, this is run after I've set the program as active window (function above):

public class MailReader
    {
[DllImport("user32.dll")] public static extern bool GetCursorPos(ref Point lpPoint);

[DllImport("gdi32.dll", CharSet = CharSet.Auto, SetLastError = true, ExactSpelling = true)] public static extern int BitBlt(IntPtr hDC, int x, int y, int nWidth, int nHeight, IntPtr hSrcDC, int xSrc, int ySrc, int dwRop);


        static Bitmap screenPixel = new Bitmap(1, 1, PixelFormat.Format32bppArgb);
        public static Color GetColorAt(Point location)
        {
            using (Graphics gdest = Graphics.FromImage(screenPixel))
            {
                using (Graphics gsrc = Graphics.FromHwnd(IntPtr.Zero)){
                    IntPtr hSrcDC = gsrc.GetHdc();
                    IntPtr hDC = gdest.GetHdc();
                    int retval = BitBlt(hDC, 0, 0, 1, 1, hSrcDC, location.X, location.Y, (int)CopyPixelOperation.SourceCopy);
                    gdest.ReleaseHdc();
                    gsrc.ReleaseHdc();
                }
            }

            return screenPixel.GetPixel(0, 0);
        }
    }

Conole program being run, this returns the correct X and Y pixels that I told it to, but the colors come back off:

namespace TestProgram.TestConsole
{
    class Program
    {
        static void Main(string[] args)
        {

            var model = new PixelInformation
            {
                X = 505,
                Y = 27,
                R = 117,
                G = 208,
                B = 50
            };
            var point = new Point();
            point.X = model.X;
            point.Y = model.Y;

            ActivateWindow.Activate("cookieGame");
            var location = PixelReader.GetColorAt(point);
            Console.WriteLine("Position X: " + point.X + " Y: " + point.Y);

            Console.WriteLine("R:" + location.R + " " + "G:" + location.G + " B:" + location.B);

            Console.ReadKey();
        }
    }
}

Answer 1

These symptoms are consistent with your system using font scaling other than 100% and the process not being DPI aware. Thus the process is subject to DPI virtualization.