BepInEx/BepInEx.Bootstrap/Entrypoint.cs

using System;
using System.Diagnostics;
using System.IO;
using System.Reflection;

namespace BepInEx.Bootstrap
{
    public static class Entrypoint
    {
        private static readonly string LocalDirectory =
            Path.GetDirectoryName(Process.GetCurrentProcess().MainModule.FileName);

        public static void Init()
        {
            AppDomain.CurrentDomain.AssemblyResolve += ResolveBepInEx;

            Linker.StartBepInEx();
        }

        private static Assembly ResolveBepInEx(object sender, ResolveEventArgs args)
        {
            var path = Path.Combine(LocalDirectory, $@"BepInEx\core\{new AssemblyName(args.Name).Name}.dll");

            if (!File.Exists(path))
                return null;

            try
            {
                return Assembly.LoadFile(path);
            }
            catch (Exception)
            {
                return null;
            }
        }
    }
}