Android应用没有从SignalR中心接收数据

Question

我已经阅读了这些主题：
如何在Android中使用SignalR
Android客户端无法获取数据，但.net客户端从SignalR服务器获取数据

我用Android编写了一个与SignalR配合使用的简单聊天系统。
它应该是客户端发送消息（通过在服务器上调用SendMessage方法），服务器应该在客户端上调用NewMessage方法。

这是我用C＃编写的ChatHub类（简化）。

public class ChatHub : Hub
{
    // Store the clients connections Id
    static readonly List<string> _connectedClients;

    public override Task OnConnected()
    {
        // Keep connections id
        // This section works fine and when the android device connects to the server,
        // Its connection id will stored.
        _connectedClients.Add(Context.ConnectionId)

        //... other codes
    }

    public void SendMessage(string message)
    {
        foreach (var connectionId in _connectedClients)
        {
            // according to the logs 
            // android device connection id exists here
            // and it works fine.
            Clients.Client(connectionId).NewMessage(message);
        }
    }
}

当android客户端连接到服务器时，在OnConnected方法上，连接ID将存储在_connectedClients并且它可以正常工作。

在ChatHub类的SendMessage方法中，我们有android设备连接ID，我确定android设备在列表中

这是我的Andoird代码：

public class ChatActivity extends AppCompatActivity
{
    // private fields
    HubConnection connection;
    HubProxy hub;
    ClientTransport transport;

    protected void onCreate(Bundle savedInstanceState) {

        Logger logger = new Logger() {
            @Override
            public void log(String message, LogLevel logLevel) {
                Log.e("SignalR", message);
            }
        };

        Platform.loadPlatformComponent(new AndroidPlatformComponent());
        connection = new HubConnection("192.168.1.100");
        hub = connection.createHubProxy("chatHub"); // case insensitivity

        transport = new LongPollingTransport(connection.getLogger());

        // no difference when using this:
        //transport = new ServerSentEventsTransport(connection.getLogger());

        // this event never fired!
        hub.subscribe(new Object() {
            public void NewMessage(String message)
            {
                Log.d("<Debug", "new message received in subscribe"); // won't work!
            }
        }

        // this event never fired!
        hub.on("NewMessage", new SubscriptionHandler() {
            @Override
            public void run() {
                Log.d("<Debug", "new message received in `on`"); // won't work!
            }
        });

        // connect to the server that works fine.
        SignalRFuture<Void> awaitConnection = connection.start(transport);
        try {
            awaitConnection.get(); // seems useless when using this or not!
        }
        catch (Exception ex) {
        }

        // this method works fine.
        hub.invoke("sendMessage", "this is a test message to the server")
        .done(new Action<Void>() {
                @Override
                public void run(Void aVoid) throws Exception {
                    Log.d("<Debug", "message sent."); // Works fine
                }
        });

    }
}

在上面的java代码中，在服务器上调用sendMessage工作正常，服务器获取消息。
但唯一的问题是服务器永远不会调用hub.on(...)或hub.subscribe(...)事件。
在一个简单的描述中，我的应用程序可以发送消息，但无法接收来自其他人的消息。
任何建议将不胜感激。

Answer 1

对于期货这是我最终获得答案的方式（请先阅读android代码的问题）：

public class ChatActivity extends AppCompatActivity
{
    // private fields
    HubConnection connection;
    HubProxy hub;
    ClientTransport transport;

    protected void onCreate(Bundle savedInstanceState) {

        Logger logger = new Logger() {
            @Override
            public void log(String message, LogLevel logLevel) {
                Log.e("SignalR", message);
            }
        };

        Platform.loadPlatformComponent(new AndroidPlatformComponent());
        connection = new HubConnection("192.168.1.100");
        hub = connection.createHubProxy("chatHub"); // case insensitivity

        /* ****new codes here**** */
        hub.subscribe(this);

        transport = new LongPollingTransport(connection.getLogger());

        /* ****new codes here**** */
        connection.start(transport);

        /* ****new codes here**** */
        /* ****seems useless but should be here!**** */
        hub.subscribe(new Object() {
            @SuppressWarnings("unused")
            public void newMessage(final String message, final String messageId, final String chatId,
                                   final String senderUserId, final String fileUrl, final String replyToMessageId) {


            }
        });


        /* ********************** */
        /* ****new codes here**** */
        /* **** the main method that I fetch data from server**** */
        connection.received(new MessageReceivedHandler() {
            @Override
            public void onMessageReceived(final JsonElement json) {
                runOnUiThread(new Runnable() {
                    public void run() {
                        JsonObject jsonObject = json.getAsJsonObject();
                        Log.e("<Debug>", "response = " + jsonObject.toString());

                    }
                });
            }
        });
        /* ********************** */

    }
}

！重要的提示：
代码的优先级很重要。 这就是我在本主题中解决问题的方法。

Answer 2

您不在客户端提供参数，这些参数应与您的旁边站点相同 。 代码应该如下：

      hub.on("NewMessage", new SubscriptionHandler1<String>() {
        @Override
        public void run(String message) {
            Log.d("<Debug", "new message received in `on`"); 
        }
    },String.class);  //do not forget say the String class in the end