c# - Overriding HandlerEx in C# Windows Service

Question

Is there any way to override the default HandlerEx in a C# Windows service within ServiceBase? All I can find is OnPowerEvent and OnCustomCommand.

For those of you wondering why I need this: OnPowerEvent doesn't handle GUID_LIDSWITCH_STATE_CHANGE. OnPowerEvent fires but doesn't indicate if the lid was closed or opened.

Here's my code:

using System;
using System.Runtime.InteropServices;
using System.ServiceProcess;

namespace KeefService
{
    public partial class Main : ServiceBase
    {
        [DllImport("user32.dll")]
        static extern bool BlockInput(bool fBlockIt);

        [DllImport("User32.dll")]
        static extern IntPtr RegisterPowerSettingNotification(IntPtr hRecipient, ref Guid PowerSettingGuid, Int32 Flags);

        static Guid GUID_LIDSWITCH_STATE_CHANGE = new Guid(0xBA3E0F4D, 0xB817, 0x4094, 0xA2, 0xD1, 0xD5, 0x63, 0x79, 0xE6, 0xA0, 0xF3);

        const int DEVICE_NOTIFY_SERVICE_HANDLE = 0x00000001;

        const int PBT_POWERSETTINGCHANGE = 0x8013;

        public Main()
        {
            InitializeComponent();
        }

        protected override bool OnPowerEvent(PowerBroadcastStatus powerStatus)
        {
            if ((int)powerStatus == PBT_POWERSETTINGCHANGE)
                BlockInput(true); //TRUE OR FALSE!?!

            return base.OnPowerEvent(powerStatus);
        }

        protected override void OnStart(string[] args)
        {
            RegisterPowerSettingNotification(this.ServiceHandle, ref GUID_LIDSWITCH_STATE_CHANGE, DEVICE_NOTIFY_SERVICE_HANDLE);
        }

        protected override void OnStop()
        {
            BlockInput(false);
        }
    }
}