动态执行委托

Question

我有一个基本上是消息处理程序的类，它接受请求，找到该消息类型的处理器，创建适当的响应并返回它。为此，我有 如下创建了一个委托public delegate Rs ProcessRequest<Rq,Rs>(Rq request);，然后在我的类中，创建了许多受支持的消息及其处理方法。问题是主进程方法应该弄清楚使用哪个进程方法找不到使用GetMethod()方法的方法。

这是整个代码，如果你能告诉我如何动态选择合适的方法然后执行它，那就是我要找的。​​p>

public delegate Rs ProcessRequest<in Rq, out Rs>(Rq request) where Rq : API.Request where Rs : API.Response;

public class WebSocketServer
{
    private WebSocketMessageHandler messageHander;

    // Incoming message handlers
    public ProcessRequest<InitUDPConnectionRq, InitUDPConnectionRs> ProcessInitUDPConnection;
    public ProcessRequest<ListenHandshakeRq, ListenHandshakeRs> ProcessListenHandshake;
    public ProcessRequest<PresenceChangeRq, PresenceChangeRs> ProcessPresenceChange;
    public ProcessRequest<ChatMessageRq, ChatMessageRs> ProcessChatMessage;
    public ProcessRequest<RDPRequestResponseRq, RDPRequestResponseRs> ProcessRDPRequestResponse;
    public ProcessRequest<RDPIncomingRequestRq, RDPIncomingRequestRs> ProcessRDPIncomingRequest;

    public WebSocketServer(WebSocketMessageHandler handler)
    {
        this.messageHander = handler;
    }

    public void processRequest(API.Request request)
    {
        String resquestType = request.GetType().Name;
        String processorName = resquestType.Substring(0, resquestType.Length - 2);
        API.Response response = null;
        // Do we have a process method for this processor
        MethodInfo methodInfo = this.GetType().GetMethod("Process" + processorName);
        if (methodInfo != null)
        {
             // Execute the method via Invoke...., but code never gets here
        }
        else
        {
            logger.Warn("Failed to find a processor for " + processorName);
            response = new ErrorRs(request.id, "Failed to find a processor for " + processorName);
        }
        sendResponse(response, request);
    }
}

现在我将这些字段分配给方法，我只是无法动态执行它们。

// Link into the hooks so we can receive requests
_appContext.ConnectionManager.Connection.webSocketServer.ProcessInitUDPConnection = ProcessInitUDPConnection;
_appContext.ConnectionManager.Connection.webSocketServer.ProcessListenHandshake = ProcessListenHandshake;
_appContext.ConnectionManager.Connection.webSocketServer.ProcessPresenceChange = ProcessPresenceChange;
_appContext.ConnectionManager.Connection.webSocketServer.ProcessChatMessage = ProcessChatMessage;

// 1 method as an example
private PresenceChangeRs ProcessPresenceChange(PresenceChangeRq request)
{
    _appContext.RosterManager.presenceChange(request.user, request.presence);
    return new PresenceChangeRs();
}

Answer 1

这里是Dictionary 用法的一些示例代码。对我来说，自定义类型太多了，无法确保它完全编译并经过测试，但应该能让你走上正轨。

public class WebSocketServer
{
    private WebSocketMessageHandler messageHander;

    // Incoming message handlers
    private Dictionary<string, System.Delegate> ProcessHandlers = new Dictionary<string, System.Delegate>();

    public void RegisterProcessHandler(string name, System.Delegate handler)
    {
        ProcessHandlers.Add(name, handler);
    }

    public void processRequest(API.Request request)
    {
        String resquestType = request.GetType().Name;
        String processorName = resquestType.Substring(0, resquestType.Length - 2);
        API.Response response = null;

        string processorName = "Process" + processorName;

        if (ProcessHandlers.ContainsKey(processorName))
        {
            System.Delegate myDelegate = ProcessHandlers[processorName]; 
            response = (API.Response)myDelegate.DynamicInvoke(request);
        }
        else
        {
            logger.Warn("Failed to find a processor for " + processorName);
            response = new ErrorRs(request.id, "Failed to find a processor for " + processorName);
        }

        sendResponse(response, request);
    }
}

注册：

var webSocketServer = _appContext.ConnectionManager.Connection.webSocketServer;
webSocketServer.RegisterProcessHandler("InitUDPConnection", ProcessInitUDPConnection);
webSocketServer.RegisterProcessHandler("ListenHandshake", ProcessListenHandshake);