使用Windows Api来调整屏幕亮度

/*
调整亮度 参数0-100
设置成功返回0
设置失败返回负数
*/
int SetGamma(int bright)
{
	void * lpGamma = NULL;
	int iArrayValue;
	WORD gMap[3][256] = {0};
	lpGamma = &gMap;
	HDC hdc = ::GetDC(NULL);
	if (NULL == hdc)
		return -1;
	for (int i = 0; i < 256; i++)
	{
		iArrayValue = i * (bright + 128);
		if (iArrayValue > 65535)
			iArrayValue = 65535;
		    gMap[0][i] =
			gMap[1][i] =
			gMap[2][i] = (WORD)iArrayValue;
	}
	if (FALSE == SetDeviceGammaRamp(hdc, lpGamma))
		return -2;
	return 0;
}