using System;
using System.Runtime.InteropServices;

namespace NoSleepMonitor
{
    static internal class NoSleepWay1
    {
       [Flags()]
        public enum EXECUTION_STATE : uint //Determine Monitor State
        {
            ES_AWAYMODE_REQUIRED = 0x00000040,
            ES_CONTINUOUS = 0x80000000,
            ES_DISPLAY_REQUIRED = 0x00000002,
            ES_SYSTEM_REQUIRED = 0x00000001
            // Legacy flag, should not be used.
            // ES_USER_PRESENT = 0x00000004
        }

        [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        private static extern EXECUTION_STATE SetThreadExecutionState(EXECUTION_STATE esFlags);

        public static void Sleep()
        {
            SetThreadExecutionState(EXECUTION_STATE.ES_CONTINUOUS);
        }

        public static void NoSleep()
        {
            SetThreadExecutionState(EXECUTION_STATE.ES_DISPLAY_REQUIRED | EXECUTION_STATE.ES_CONTINUOUS);
        }
    }
}

using System.Runtime.InteropServices;


namespace NoSleepMonitor
{
    public class NoSleepWay2
    {
        [DllImport("user32", EntryPoint = "SystemParametersInfo", CharSet = CharSet.Auto, SetLastError = true)]
        private static extern int SystemParametersInfo(int uAction, int uParam, string lpvParam, int fuWinIni);

        private const int SPI_SETSCREENSAVEACTIVE = 0x0011;

        public static void NoSleep()
        {
            SystemParametersInfo(SPI_SETSCREENSAVEACTIVE, 0, "0", 0);
        }
        public static void Sleep()
        {
            SystemParametersInfo(SPI_SETSCREENSAVEACTIVE, 1, "0", 0);
        }
    }
}