SignalR 客户端未收到服务器消息

Question

我的 SignalR 客户端没有收到来自服务器的任何消息。我在这里错过了什么？

服务器中心

namespace DoneITWebAPI.Hubs
{
    public interface ITypedHubClient
    {
        Task BroadcastMessage(string name, string message);
    }

    public class ServiceStatusHub : Hub<ITypedHubClient>
    {
        public void Send(string name, string message)
        {
            Clients.All.BroadcastMessage(name, message);
        }

    }
}

控制器

[Route("api/[controller]")]
[ApiController]
public class DemoController : Controller
{
    IHubContext<ServiceStatusHub, ITypedHubClient> _chatHubContext;
    public DemoController(IHubContext<ServiceStatusHub, ITypedHubClient> chatHubContext)
    {
        _chatHubContext = chatHubContext;
    }

    // GET: api/values
    [HttpGet]
    public IEnumerable<string> Get()
    {
        _chatHubContext.Clients.All.BroadcastMessage("ReceiveMessage", "test");
        return new string[] { "value1", "value2" };
    }
}

控制台客户端应用程序

class Program
{
    static void Main(string[] args)
    {
        var connection = new HubConnectionBuilder()
        .WithUrl("http://localhost:64165/ServiceStatusHub")
        .Build();

        connection.On<string, string>("ReceiveMessage", (user, message) =>
        {
            GetMessage(user, message);
        });

        connection.StartAsync();

        Console.ReadKey();
    }


    public static void GetMessage(string user, string message)
    {
        //Not hitting here
    }
}

Answer 1

My SignalR client doesn't receive any messages from the server. What am I missing here?

根据您的代码，我们可以发现您使用了 strongly typed hubs，并且您在控制台应用程序上将客户端方法定义并命名为 ReceiveMessage。

为了使您可以按预期调用该客户端方法，您可以尝试如下修改您的中心代码。

public interface ITypedHubClient
{
    Task ReceiveMessage(string name, string message);
}

public class ServiceStatusHub : Hub<ITypedHubClient>
{
    public void Send(string name, string message)
    {
        Clients.All.ReceiveMessage(name, message);
    }

}

并更改 API 操作中的代码

_chatHubContext.Clients.All.ReceiveMessage("system", "test");

测试结果