如何在C#中检测显示器上像素的颜色？

using System;
using System.Drawing;
using System.Runtime.InteropServices;

class Program
{
    [DllImport("user32.dll")]
    static extern IntPtr GetDC(IntPtr hwnd);

    [DllImport("user32.dll")]
    static extern Int32 ReleaseDC(IntPtr hwnd, IntPtr hdc);

    [DllImport("gdi32.dll")]
    static extern uint GetPixel(IntPtr hdc, int nXPos, int nYPos);

    static void Main(string[] args)
    {
        Point cursorPosition = Cursor.Position;
        IntPtr hdc = GetDC(IntPtr.Zero);
        uint color = GetPixel(hdc, cursorPosition.X, cursorPosition.Y);
        ReleaseDC(IntPtr.Zero, hdc);

        Color pixelColor = Color.FromArgb((int)color);
        Console.WriteLine("Pixel color at ({0}, {1}) is: {2}", cursorPosition.X, cursorPosition.Y, pixelColor.ToString());
    }
}