调用SignalR Hub不适用于Asp.Net Core Web API

我是SignalR的新手。我正在尝试设置一个Asp.Net Core WebAPI，以便其他客户端可以使用SignalR连接到它并获取实时数据。我的Hub类是：

public class TimeHub : Hub
{
    public async Task UpdateTime(string message)
    {
        await Clients.All.SendAsync("ReceiveMessage", message);
    }
}

我有一个中继课程，如下所示：

public class TimeRelay : ITimeRelay
{
    private readonly IHubContext<TimeHub> _timeHubContext;

    public TimeRelay(IHubContext<TimeHub> context)
    {

        _timeHubContext = context;
        Task.Factory.StartNew(async () =>
        {
            while (true)
            {
                await context.Clients.All.SendAsync("UpdateTime", DateTime.Now.ToShortDateString());
                Thread.Sleep(2000);
            }
        });
    }
}

启动类：

public void ConfigureServices(IServiceCollection services)
{
    services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1);

    services.AddSignalR();
}

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
    app.UseDeveloperExceptionPage();

    app.UseHttpsRedirection();

    app.UseSignalR((x) =>
    {
        x.MapHub<TimeHub>("/timeHub");
    });
    app.UseMvc();
}

客户端是一个控制台应用程序，代码为：

class Program
{    
    static Action<string> OnReceivedAction = OnReceived;

    static void Main(string[] args)
    {
        Connect();
        Console.ReadLine();
    }

    private static async void Connect()
    {
        var hubConnectionBuilder = new HubConnectionBuilder();

        var hubConnection = hubConnectionBuilder.WithUrl("http://localhost:60211/timeHub").Build();

        await hubConnection.StartAsync();

        var on = hubConnection.On("ReceiveMessage", OnReceivedAction);

        Console.ReadLine();    
        on.Dispose();
        await hubConnection.StopAsync();
    }

    static void OnReceived(string message)
    {
        System.Console.WriteLine($"{message}");
    }
}

我尝试调试该应用程序。客户端TimeHub成功连接。Clients.All客户端连接后，连接数从0更改为1。但是，当await context.Clients.All.SendAsync("UpdateTime", DateTime.Now.ToShortDateString());执行时，UpdateTimein中的函数TimeHub未得到执行，并且客户端未得到任何消息。

我在课堂上尝试使用"UpdateTime"，"SendMessage"和"ReceiveMessage"作为方法。没事。有人可以指出我的错误。Clients.All.SendAsyncTimeRelay