c#配合c++調節螢屏亮度，非伽馬以及RGB方案

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
#include <windows.h>
#include <iostream>
#include <Ntddvdeo.h>
using namespace std;

#define IOCTL_VIDEO_QUERY_SUPPORTED_BRIGHTNESS  CTL_CODE(FILE_DEVICE_VIDEO, 0x125, METHOD_BUFFERED, FILE_ANY_ACCESS)
#define IOCTL_VIDEO_QUERY_DISPLAY_BRIGHTNESS 	CTL_CODE(FILE_DEVICE_VIDEO, 0x126, METHOD_BUFFERED, FILE_ANY_ACCESS)
#define IOCTL_VIDEO_SET_DISPLAY_BRIGHTNESS 		CTL_CODE(FILE_DEVICE_VIDEO, 0x127, METHOD_BUFFERED, FILE_ANY_ACCESS)


int setBrightness(int level)
{
	HANDLE h;
	DWORD nOutBufferSize = 256;
	BYTE SupportedBrightness[256];
	DWORD g_supportedLevelCount;
	DISPLAY_BRIGHTNESS DisplayBrightness;

	memset(SupportedBrightness, 0, sizeof(SupportedBrightness));

	/* use createfile function to open lcd.
	* url from microsoft about IOCTL code.
	*  http://msdn.microsoft.com/en-us/library/windows/desktop/aa372703%28v=vs.85%29.aspx
	*/

	/*
	* char* 和 wchar_t* 互相轉換參考博客
	* https://www.cnblogs.com/icqw/p/4614877.html
	*/
	/*
	* c++代碼參考博客
	* https://blog.csdn.net/weixin_34111819/article/details/86328019
	*/
	char temchar[] = "\\\\.\\LCD";
	char* szSour = temchar;
	WCHAR Temp[128] = { 0 };
	mbstowcs(Temp, szSour, strlen(szSour));
	h = CreateFile(Temp, GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, 0);
	if (h == INVALID_HANDLE_VALUE) {
		printf("Open \\\\.\\LCD error");
		exit(1);
	}

	/* Query for display supported level */
	if (!DeviceIoControl(h, IOCTL_VIDEO_QUERY_SUPPORTED_BRIGHTNESS, NULL, 0, SupportedBrightness, nOutBufferSize, &g_supportedLevelCount, NULL)) {
		printf("IOCTL_VIDEO_QUERY_SUPPORTED_BRIGHTNESS error - %d, - buffer: %d ", g_supportedLevelCount, nOutBufferSize);
		exit(1);
	}
	if (g_supportedLevelCount == 0)  	/* 0 means not supported */
	{
		printf("\nLCD not support LEVEL COUNT", g_supportedLevelCount);
		exit(1);
	}

	DisplayBrightness.ucDisplayPolicy = 0;
	DisplayBrightness.ucACBrightness = level;
	DisplayBrightness.ucDCBrightness = level;

	/* Set display backlight level */
	nOutBufferSize = sizeof(DisplayBrightness);
	if (!DeviceIoControl(h, IOCTL_VIDEO_SET_DISPLAY_BRIGHTNESS, (DISPLAY_BRIGHTNESS*)&DisplayBrightness, nOutBufferSize, NULL, 0, &nOutBufferSize, NULL)) {
		printf("IOCTL_VIDEO_SET_SUPPORTED_BRIGHTNESS error - %d, - buffer: %d ", g_supportedLevelCount, nOutBufferSize);
		exit(1);
	}

	Sleep(500); /* delay for some time while wmi event changed */
	nOutBufferSize = sizeof(DisplayBrightness);
	if (!DeviceIoControl(h, IOCTL_VIDEO_QUERY_DISPLAY_BRIGHTNESS, NULL, 0, (DISPLAY_BRIGHTNESS*)&DisplayBrightness, nOutBufferSize, &nOutBufferSize, NULL)) {
		printf("IOCTL_VIDEO_QUERY_SUPPORTED_BRIGHTNESS error - %d, - buffer: %d ", g_supportedLevelCount, nOutBufferSize);
		exit(1);
	}
	printf("\nBrightness_AC: %d\nBrightness_DC: %d", DisplayBrightness.ucACBrightness, DisplayBrightness.ucDCBrightness);
}


int main(int argc, char* argv[]) {
	///* program with arguments support */
	//if (argc == 3 && strcmp("-b", argv[1]) == 0) {
	//	setBrightness(atoi(argv[2]));
	//}
	//else {
	//	help();
	//}
	int a;
	cin >> a;
	setBrightness(a);
	return 0;
}

編譯環境是VS，眾所周知VS對代碼的要求相對嚴格，所以這位大佬的代碼有些部分需要修改，在這里我會指出修改地方以及對修改的部分進行解釋，

首先#include <Ntddvdeo.h>直接參考就可以了不要加前綴，VS會自動尋找這個頭檔案的，

	char temchar[] = "\\\\.\\LCD";
	char* szSour = temchar;
	WCHAR Temp[128] = { 0 };
	mbstowcs(Temp, szSour, strlen(szSour));
	h = CreateFile(Temp, GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, 0);

其次這里的Temp引數，之前大佬的寫法是直接“\\\\.\\LCD”，但是這個引數的位置是填到一個WCHAR型別的引數，所以我們要對其進行轉換，在轉換的程序中VS不允許使用char*指標指向一個字串常量，所以我們要先將這個字串常量賦值給一個字符陣列，然后再用指標指向它就行了，轉換的方法在另一位大佬的博客中，我在代碼中已經作為注釋給出地址了（感謝各個前輩們做出的貢獻），

最后我要注明一下，這個int setBrightness(int level)中的level的范圍是0到100，雖然大多數情況下調到0也能看清，但是萬一呢是吧，最好測驗的時候別調到零，

上面的是c++代碼現在讓我們來做成c#模塊，（這個模塊文末我會放出連接，有百度云和CSDN兩個連接，還有gitHub有全部的源代碼）我們的思路是將C++編譯成DLL模塊，然后由c#參考，并在C#中封裝成模塊的方式來供C#呼叫，

下面是c++封裝DLL的教程（正在準備材料，還沒寫完，先存著）