WinAPI.cs

using System;
using System.Runtime.InteropServices;

namespace MusicBeePlugin
{
    [Flags]
    public enum EXECUTION_STATE : uint
    {
        ES_AWAYMODE_REQUIRED = 0x00000040,
        ES_CONTINUOUS = 0x80000000,
        ES_DISPLAY_REQUIRED = 0x00000002,
        ES_SYSTEM_REQUIRED = 0x00000001
    }

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

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