DarkRift.Server.PluginFactory.AddFile C# (CSharp) Method

        internal void AddFile(string file, DependencyResolutionStrategy dependencyResolutionStrategy, string searchedDirectory)
        {
            //Check the file is a dll
            if (Path.GetExtension(file) != ".dll")
                throw new ArgumentException("The filepath supplied was not a DLL library.");

            //Check the file exists
            if (!File.Exists(file))
                throw new FileNotFoundException("The specified filepath does not exist.");

            //Log
            logger.Trace($"Searching '{file}' for plugins.");

            // Setup assembly resolver to help find dependencies recursively in the folder heirachy of the plugin
            AppDomain.CurrentDomain.AssemblyResolve += LoadFromSameFolder;

            Assembly LoadFromSameFolder(object sender, ResolveEventArgs args)
            {
                string rootFolderPath;
                if (dependencyResolutionStrategy == DependencyResolutionStrategy.RecursiveFromFile)
                {
                    rootFolderPath = Path.GetDirectoryName(file);
                }
                else if (searchedDirectory != null)
                {
                    rootFolderPath = searchedDirectory;
                }
                else
                {
                    return null;
                }

                string assemblyPath = SearchForFile(rootFolderPath, new AssemblyName(args.Name).Name + ".dll");
                if (assemblyPath == null)
                    return null;

                return Assembly.LoadFrom(assemblyPath);
            }

            //Load the assembly
            Assembly assembly;
            try
            {
                assembly = Assembly.LoadFrom(Path.GetFullPath(file));
            }
            catch (Exception e)
            {
                logger.Error($"{file} could not be loaded as an exception occurred.", e);
                return;
            }

            //Get the types in the assembly
            IEnumerable<Type> enclosedTypes;
            try
            {
                enclosedTypes = assembly.GetTypes();
            }
            catch (ReflectionTypeLoadException e)
            {
                logger.Error(
                    $"Failed to load one or more plugins from DLL file '{file}', see following logs for more info.\n\nIf this file is a DarkRift plugin rebuilding this plugin may help. Make sure it is built against the same .NET target as DarkRift is running and built to a compatible version ({Environment.Version}).\n\nThis exception can also occur when an unmanaged DLL is loaded by DarkRift because it is in a plugin search path. If this is the case, consider moving the unmanaged library out of any plugin search paths (https://docs.microsoft.com/en-us/dotnet/core/dependency-loading/default-probing#unmanaged-native-library-probing) or modify the plugin search path configuration to avoid discovering the library (e.g. reference individual DLL files instead of the containing directory).",
                    e
                );

                foreach (Exception loaderException in e.LoaderExceptions)
                {
                    logger.Error("Additional exception detail from LoaderExceptions property:", loaderException);
                }

                // The types unable to be loaded will be null here!
                enclosedTypes = e.Types.Where(t => t != null);
            }

            //Find the types that are plugins
            foreach (Type enclosedType in enclosedTypes)
            {
                if (enclosedType.IsSubclassOf(typeof(PluginBase)) && !enclosedType.IsAbstract)
                {
                    //Add the plugin
                    AddType(enclosedType);
                }
            }

            // Remove resolver again
            AppDomain.CurrentDomain.AssemblyResolve -= LoadFromSameFolder;
        }