C#调节电脑亮度

 SetBrightness(int.Parse(statics));//参数是亮度参数
 [DllImport("gdi32.dll")]
        private unsafe static extern bool SetDeviceGammaRamp(Int32 hdc, void* ramp);
        private static bool initialized = false;
        private static Int32 hdc;
        private static int a;
        private static void InitializeClass()
        {
            if (initialized)
                return;
            hdc = Graphics.FromHwnd(IntPtr.Zero).GetHdc().ToInt32();
            initialized = true;
        }
        public static unsafe bool SetBrightness(int brightness)
        {
            InitializeClass();
            if (brightness > 255)
                brightness = 255;
            if (brightness < 0)
                brightness = 0;
            short* gArray = stackalloc short[3 * 256];
            short* idx = gArray;
            for (int j = 0; j < 3; j++)
            {
                for (int i = 0; i < 256; i++)
                {
                    int arrayVal = i * (brightness + 128);
                    if (arrayVal > 65535)
                        arrayVal = 65535;
                    *idx = (short)arrayVal;
                    idx++;
                }
            }
            bool retVal = SetDeviceGammaRamp(hdc, gArray);
            return retVal;
        }