引数に２つの解像度を指定して切り替えるC++コード

DPISwitcher.cpp

#include <iostream>
#include <string>
#include <Windows.h>

int main(int argc, char* argv[]) {

	if (argc != 6)
	{
		printf("Please arguments: monitorNo width1 height1 width2 height2\n");
		getchar();
		return 0;
	}

	DWORD monitorNo = std::stoi(argv[1]);
	DWORD width = std::stoi(argv[2]);
	DWORD height = std::stoi(argv[3]);
	DWORD width2 = std::stoi(argv[4]);
	DWORD height2 = std::stoi(argv[5]);

	DISPLAY_DEVICE device;
	device.cb = sizeof(DISPLAY_DEVICE);
	EnumDisplayDevices(NULL, monitorNo, &device, NULL);

	DEVMODE checkMode;
	EnumDisplaySettings(device.DeviceName, ENUM_CURRENT_SETTINGS, &checkMode);

	if (checkMode.dmPelsWidth == width && checkMode.dmPelsHeight == height)
	{		
		width = width2;
		height = height2;			 
	}

	DEVMODE submitMode = { 0 };
	submitMode.dmSize = sizeof(submitMode);
	submitMode.dmPelsWidth = width;
	submitMode.dmPelsHeight = height;
	submitMode.dmFields = DM_PELSWIDTH | DM_PELSHEIGHT;

	DWORD ret = ChangeDisplaySettingsEx(device.DeviceName, &submitMode, NULL, 0, NULL);
		
	return ret;
}