Asp.Net Core：信号器：队列：将组名传递到队列中

Question

我有一个使用 signalr 的 asp.net 核心项目。我正在尝试通过队列将组名作为参数传递给我的后台服务。在我的集线器中，我编写了一个函数来使用从 javascript 传入的组名加入组。我在浏览器中只收到一条消息。

这是我的代码：

LiveDataHub.cs:

public sealed class LiveDataHub : Hub     
{           
    private readonly IMyBackgroundQueue _queue;
    public LiveDataHub(IMyBackgroundQueue queue) => _queue = queue;

    public async Task JoinToGroup(string group)
    {
        Console.WriteLine("New group joined: " + group);            
        await _queue.QueueAsync(group);
        await Groups.AddToGroupAsync(Context.ConnectionId, group);
        await Clients.Group(group).SendAsync("Send", $"{Context.ConnectionId} has joined the group {group}.");
    }
}

我的背景队列.cs

public interface IMyBackgroundQueue
{
    ValueTask QueueAsync(string item);

    IAsyncEnumerable<string> DequeueAllAsync(
        CancellationToken cancellationToken);
}

public class MyBackgroundQueue : IMyBackgroundQueue
{
    //private readonly Channel<string> _channel = Channel.CreateUnbounded<string>();
    private readonly Channel<string> _channel;
    public MyBackgroundQueue(int capacity)
    {            
        var options = new BoundedChannelOptions(capacity)
        {
            FullMode = BoundedChannelFullMode.Wait
        };
        _channel = Channel.CreateBounded<string>(options);
    }
    public ValueTask QueueAsync(string item) => _channel.Writer.WriteAsync(item);        
    public IAsyncEnumerable<string> DequeueAllAsync(CancellationToken ct) =>
        _channel.Reader.ReadAllAsync(ct);
}

MyBackgroundService.cs:

public class MyBackgroundService : BackgroundService
{
    private readonly IHubContext<LiveDataHub> _hub;
    public IMyBackgroundQueue _queue { get; }
    public MyBackgroundService(IHubContext<LiveDataHub> hub, IMyBackgroundQueue queue)
    {
        _hub = hub;
        _queue = queue;
    }

    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
        while (!stoppingToken.IsCancellationRequested)
        {
            var eventMessage = new Models.EventMessage($"Id_{ Guid.NewGuid():N}", $"Title_{Guid.NewGuid():N}", DateTime.Now.ToString("yyyy-MM-dd hh:mm:ss"));                
            await foreach(var _item in _queue.DequeueAllAsync(stoppingToken))
            {
                Console.WriteLine("group name: " + _item.ToString());
                await _hub.Clients.Group(_item.ToString()).SendAsync("onMessageReceived", eventMessage, stoppingToken);
            }
            await Task.Delay(1000, stoppingToken);
        }


        
    }
    public override async Task StopAsync(CancellationToken stoppingToken)
    {
        await base.StopAsync(stoppingToken);
    }
}

Startup.cs：

public void ConfigureServices(IServiceCollection services)
    {
        services.AddRazorPages();
        services.AddSignalR(hubPotions=> { hubPotions.EnableDetailedErrors = true; });

        services.AddHostedService<MyBackgroundService>();            
        services.AddSingleton<IMyBackgroundQueue, MyBackgroundQueue>(ctx => {
            return new MyBackgroundQueue(100);
        }); // I think the error is here on this line but I can't seem to figure out what it is
    }

javascript.js

const signalrConnection = new signalR.HubConnectionBuilder()
.withUrl("/messagebroker")
.configureLogging(signalR.LogLevel.Information)
.build();

signalrConnection.start().then(function () {
console.log("SignalR Hub Connected");

signalrConnection.invoke("JoinToGroup", "Group01")
    .catch(function (err) {
        console.error(err.toString());
    });

}).catch(function (err) {
    signalrConnection.stop();
    console.error(err.toString());
});