问如何在插件之间进行通信？

EN

// this is your host
public interface IHostController {
    // names of all loaded plugins
    string[] Plugins { get; }
    void StartPlugin(string name);
    void StopPlugin(string name);
}
public interface IPlugin {
    // with this method you will pass plugin a reference to host
    void Init(IHostController host);
    void Start();
    void Stop();                
}
// helper class to combine app domain and loader together
public class PluginInfo {
    public AppDomain Domain { get; set; }
    public RemoteLoader Loader { get; set; }
}

public class RemoteLoader : MarshalByRefObject {
    private Assembly _pluginAassembly;
    private IPlugin _instance;
    private string _name;

    public void Init(IHostController host, string assemblyPath) {
        // note that you pass reference to controller here
        _name = Path.GetFileNameWithoutExtension(assemblyPath);
        if (_pluginAassembly == null) {
            _pluginAassembly = AppDomain.CurrentDomain.Load(File.ReadAllBytes(assemblyPath));
        }

        // Required to identify the types when obfuscated
        Type[] types;
        try {
            types = _pluginAassembly.GetTypes();
        }
        catch (ReflectionTypeLoadException e) {
            types = e.Types.Where(t => t != null).ToArray();
        }

        var type = types.FirstOrDefault(t => t.GetInterface("IPlugin") != null);
        if (type != null && _instance == null) {
            _instance = (IPlugin) Activator.CreateInstance(type, null, null);
            // propagate reference to controller futher
            _instance.Init(host);
        }
    }

    public string Name => _name;
    public bool IsStarted { get; private set; }

    public void Start() {
        if (_instance == null) {
            return;
        }
        _instance.Start();
        IsStarted = true;
    }

    public void Stop() {
        if (_instance == null) {
            return;
        }
        _instance.Stop();
        IsStarted = false;
    }
}

// note : inherits from MarshalByRefObject and implements interface
public class HostController : MarshalByRefObject, IHostController {        
    private readonly Dictionary<string, PluginInfo> _plugins = new Dictionary<string, PluginInfo>();

    public void ScanAssemblies(params string[] paths) {
        foreach (var path in paths) {
            var setup = new AppDomainSetup();                
            var domain = AppDomain.CreateDomain(Path.GetFileNameWithoutExtension(path), null, setup);
            var assemblyPath = Assembly.GetExecutingAssembly().Location;
            var loader = (RemoteLoader) domain.CreateInstanceFromAndUnwrap(assemblyPath, typeof (RemoteLoader).FullName);
            // you are passing "this" (which is IHostController) to your plugin here
            loader.Init(this, path);                          
            _plugins.Add(loader.Name, new PluginInfo {
                Domain = domain,
                Loader = loader
            });
        }
    }

    public string[] Plugins => _plugins.Keys.ToArray();

    public void StartPlugin(string name) {
        if (_plugins.ContainsKey(name)) {
            var p = _plugins[name].Loader;
            if (!p.IsStarted) {
                p.Start();
            }
        }
    }

    public void StopPlugin(string name) {
        if (_plugins.ContainsKey(name)) {
            var p = _plugins[name].Loader;
            if (p.IsStarted) {
                p.Stop();
            }
        }
    }
}

public class FirstPlugin : IPlugin {
    const string Name = "First Plugin";

    public void Init(IHostController host) {
        Console.WriteLine(Name + " initialized");
    }

    public void Start() {
        Console.WriteLine(Name + " started");
    }

    public void Stop() {
        Console.WriteLine(Name + " stopped");
    }
}

public class FirstPlugin : IPlugin {
    const string Name = "Second Plugin";
    private Timer _timer;
    private IHostController _host;

    public void Init(IHostController host) {
        Console.WriteLine(Name + " initialized");
        _host = host;
    }

    public void Start() {
        Console.WriteLine(Name + " started");
        Console.WriteLine("Will try to restart first plugin every 5 seconds");
        _timer = new Timer(RestartFirst, null, 5000, 5000);
    }

    int _iteration = 0;
    private void RestartFirst(object state) {
        // here we talk with a host and request list of all plugins
        foreach (var plugin in _host.Plugins) {
            Console.WriteLine("Found plugin " + plugin);
        }
        if (_iteration%2 == 0) {
            Console.WriteLine("Trying to start first plugin");
            // start another plugin from inside this one
            _host.StartPlugin("Plugin1");
        }
        else {
            Console.WriteLine("Trying to stop first plugin");
            // stop another plugin from inside this one
            _host.StopPlugin("Plugin1");
        }
        _iteration++;
    }

    public void Stop() {
        Console.WriteLine(Name + " stopped");
        _timer?.Dispose();
        _timer = null;
    }
}

static void Main(string[] args) {
    var host = new HostController();
    host.ScanAssemblies(@"path to your first Plugin1.dll", @"path to your second Plugin2.dll");                  
    host.StartPlugin("Plugin2");
    Console.ReadKey();
}

First Plugin initialized
Second Plugin initialized
Second Plugin started
Will try to restart first plugin every 5 seconds
Found plugin Plugin1
Found plugin Plugin2
Trying to start first plugin
First Plugin started
Found plugin Plugin1
Found plugin Plugin1
Found plugin Plugin2
Trying to stop first plugin
Found plugin Plugin2
Trying to stop first plugin
First Plugin stopped
First Plugin stopped
Found plugin Plugin1
Found plugin Plugin2
Trying to stop first plugin