将java转换为c＃的问题

Question

I'm attempting to convert the code located at How to use signalr in android Service from java to c# and have been making some progress. I'm now stuck at the final method. The java code is:

private void startSignalR() {
    Platform.loadPlatformComponent(new AndroidPlatformComponent());
    mInstance.setmHubConnection();
    mInstance.setHubProxy();
    ClientTransport clientTransport = new ServerSentEventsTransport(mInstance.mHubConnection.getLogger());
    SignalRFuture<Void> signalRFuture = mInstance.mHubConnection.start(clientTransport);

    try {
        signalRFuture.get();
    } catch (InterruptedException | ExecutionException e) {
        Log.e("SimpleSignalR", e.toString());
        return;
    }

    mInstance.sendMessage(MainActivity.unm,"Hello All!");

    String CLIENT_METHOD_BROADAST_MESSAGE = "recievedMessage";
    mInstance.mHubProxy.on(CLIENT_METHOD_BROADAST_MESSAGE,
            new SubscriptionHandler2<String,LoginInfo>() {
                @Override
                public void run(final String msg,final LoginInfo loginInfo) {
                    final String finalMsg = loginInfo.FullName  + "  says " + loginInfo.Password;
                Intent intent = new Intent();
                intent.setAction(MY_ACTION);
                intent.putExtra("DATAPASSED", finalMsg);
                sendBroadcast(intent);
            }
        }
        , String.class,LoginInfo.class);
}

Using a java to c# converter, this translated to:

    private void startSignalR()
    {
        Platform.loadPlatformComponent(new AndroidPlatformComponent());
        mInstance.setmHubConnection();
        mInstance.setHubProxy();
        ClientTransport clientTransport = new ServerSentEventsTransport(mInstance.mHubConnection.Logger);
        SignalRFuture<Void> signalRFuture = mInstance.mHubConnection.Start(clientTransport);

        try
        {
            signalRFuture.get();
        }
        catch (Exception e) when (e is InterruptedException || e is ExecutionException)
        {
            // Log.e("SimpleSignalR", e.ToString());
            return;
        }

        mInstance.sendMessage("", "Hello All!");

        string CLIENT_METHOD_BROADAST_MESSAGE = "recievedMessage";
        //String CLIENT_METHOD_BROADAST_MESSAGE = "messageReceived";
        mInstance.mHubProxy.on(CLIENT_METHOD_BROADAST_MESSAGE, new SubscriptionHandler2AnonymousInnerClass(this)
           , typeof(string), typeof(LoginInfo));
    }

    private class SubscriptionHandler2AnonymousInnerClass : SubscriptionHandler2<string, LoginInfo>
    {
        private readonly SignalRSrv outerInstance;

        public SubscriptionHandler2AnonymousInnerClass(SignalRSrv outerInstance)
        {
            this.outerInstance = outerInstance;
        }

        //JAVA TO C# CONVERTER WARNING: 'final' parameters are not available in .NET:
        //ORIGINAL LINE: @Override public void run(final String msg,final LoginInfo loginInfo)
        public override void run(string msg, LoginInfo loginInfo)
        {
            //JAVA TO C# CONVERTER WARNING: The original Java variable was marked 'final':
            //ORIGINAL LINE: final String finalMsg = loginInfo.FullName + "  says " + loginInfo.Password;
            string finalMsg = loginInfo.FullName + "  says " + loginInfo.Password;
            Intent intent = new Intent();
            intent.Action = MY_ACTION;
            intent.PutExtra("DATAPASSED", finalMsg);
            sendBroadcast(intent);
        }
    }

This, of course, generated several errors in Visual Studio 2017.

First, the line Platform.loadPlatformComponent(new AndroidPlatformComponent()); generated the error Platform is inaccessible due to its protection level . Platform in Xamarin for Visual Studio 2017 is indeed protected and is a internal class in System and I cannot change this, so I'm at a loss as how to proceed with it. The same line generates the error The type or namespace name 'AndroidPlatformComponent' could not be found , these errors a numerous and not unexpected I just can't find an equivalent to AndroidPlatformComponent in Visual Studio 2017 so I'm at a loss as how to solve this one.

Next, on this line ClientTransport clientTransport = new ServerSentEventsTransport(mInstance.mHubConnection.Logger); generates the error The type or namespace name 'ClientTransport' could not be found , I was also unable to find an equivalent to this and again I'm at a loss as to proceed. Also on this line, .Logger is not defined for the hub connection, apparently it's .getLogger() in java, I was unable to find an equivalent for this one as well.

Next the line SignalRFuture<Void> signalRFuture = mInstance.mHubConnection.Start(clientTransport);' generates the error 1The type or namespace name 'SignalRFuture<>' could not be found SignalRFuture<Void> signalRFuture = mInstance.mHubConnection.Start(clientTransport);' generates the error 1The type or namespace name 'SignalRFuture<>' could not be found , this seemes to be specific to SignalR, again, I am unable to find an equivalent.

The next one has me totally stumped, the line private class SubscriptionHandler2AnonymousInnerClass : SubscriptionHandler2<string, LoginInfo> generates the error The type or namespace name 'SubscriptionHandler2<,>' could not be found . I've looked everywhere online and read up on AnonymousInnerClass, but it was not help with this.

I'm hoping that the users here are more familiar with SignalR and the differences between c# functionality and java functionality. I'm not at all familiar with java nor am I familiar with SignalR and foreground services.

Answer 1

As it turns out, the last method in the java code I was converting was wiring up an event to pass the message received from the hub to the activity. In c# / Visual Studio (2017), that's done very differently which is why I didn't understand/recognize what was going on. So I created a handler in C# and execute a popup message for the message. This in itself may pose problems, but at least I know what's going on. This is the code I wrote to start SignalR from within the service and WireUp the handler:

    private void startSignalR()
    {
        // Company, Department, and section are private variables
        // their values are pulled from the intent bundle 
        // in the OnBind method, that code is:
        //     Bundle bundlee = intent.GetBundleExtra("TheBundle");
        //     MyUser = bundlee.GetParcelable("MyUser") as User;
        // This information is put into the bundle when the user is logged in.
        // I then pass that information to the SignalR client 
        // when I set the hub connection and placed on the querystring to the hub.

        mInstance.setmHubConnection(username, firstname,lastname,company,department,section);
        mInstance.setHubProxy();

        try
        {
            // Connect the client to the hup
            mInstance.mHubConnection.Start();
            // Set the event handler
            mInstance.WireUp();

        }
        catch (System.Exception e) when (e is InterruptedException || e is ExecutionException)
        {
            ShowMessage("Error: + e.Message)
        }
    }

This is the WireUp code, this is a method in the client code:

    public void WireUp()
    {
        // set the event handler
        mHubProxy.On("broadcastMessage", (string platform, string message) =>
        {
            if (OnMessageReceived != null)
                OnMessageReceived(this, string.Format("{0}: {1}", platform, message));
        });
    }

As I had anticipated, the popup message won't appear when the app is in the background, so I'm researching a workaround