se-launcher/PluginLoader/Data/LocalPlugin.cs

using System.Diagnostics;
using System.Reflection;
using Sandbox.Graphics.GUI;
using VRage;

namespace PluginLoader.Data;

public class LocalPlugin : PluginData
{
    private LocalPlugin()
    {
    }

    public LocalPlugin(string dll)
    {
        Id = dll;
        Status = PluginStatus.None;
    }

    public override string Source => MyTexts.GetString(MyCommonTexts.Local);

    public override string Id
    {
        get => base.Id;
        set
        {
            base.Id = value;
            if (File.Exists(value))
                FriendlyName = Path.GetFileName(value);
        }
    }

    public override Assembly GetAssembly()
    {
        if (File.Exists(Id))
        {
            AppDomain.CurrentDomain.AssemblyResolve += LoadFromSameFolder;
            var a = Assembly.LoadFile(Id);
            Version = a.GetName().Version;
            return a;
        }

        return null;
    }

    public override string ToString()
    {
        return Id;
    }

    public override void Show()
    {
        var file = Path.GetFullPath(Id);
        if (File.Exists(file))
            Process.Start("explorer.exe", $"/select, \"{file}\"");
    }

    private Assembly LoadFromSameFolder(object sender, ResolveEventArgs args)
    {
        if (args.RequestingAssembly.IsDynamic)
            return null;

        if (args.Name.Contains("0Harmony") || args.Name.Contains("SEPluginManager"))
            return null;

        var location = args.RequestingAssembly.Location;
        if (string.IsNullOrWhiteSpace(location) || !Path.GetFullPath(location)
                                                        .StartsWith(Path.GetDirectoryName(Id),
                                                                    StringComparison.OrdinalIgnoreCase))
            return null;

        var folderPath = Path.GetDirectoryName(location);
        var assemblyPath = Path.Combine(folderPath, new AssemblyName(args.Name).Name + ".dll");
        if (!File.Exists(assemblyPath))
            return null;

        var assembly = Assembly.LoadFile(assemblyPath);
        LogFile.WriteLine("Resolving " + assembly.GetName().Name + " for " + args.RequestingAssembly.FullName);

        var main = Main.Instance;
        if (!main.Config.IsEnabled(assemblyPath))
            main.List.Remove(assemblyPath);

        return assembly;
    }

    public override void GetDescriptionText(MyGuiControlMultilineText textbox)
    {
        textbox.Visible = false;
        textbox.Clear();
    }
}