c#中怎樣取得某座標點的顏色

// x,y 分別爲x軸，y軸座標   返回System.Drawing.Color 能夠直接顯示

public System.Drawing.Color GetPixelColor(int x, int y)
{
IntPtr hdc = GetDC(IntPtr.Zero);
uint pixel = GetPixel(hdc, x, y);
ReleaseDC(IntPtr.Zero, hdc);
Color color = Color.FromArgb((int)(pixel & 0x000000FF),
(int)(pixel & 0x0000FF00) >> 8,
(int)(pixel & 0x00FF0000) >> 16);
return color;
}

//定義一個定時器   獲取當前座標上的像素點顏色
private void timer_Tick(object sender, EventArgs e)
{
textBox1.Text = GetPixelColor(Cursor.Position.X, Cursor.Position.Y).R.ToString() + " " + GetPixelColor(Cursor.Position.X, Cursor.Position.Y).G.ToString() + " " + GetPixelColor(Cursor.Position.X, Cursor.Position.Y).B.ToString();
}