SignalR 项目应用Demo

1.此 Demo 服务端环境: .NET Core 2.2,WebAPI, 客户端环境: 类库 EF4.7.2, 应用场景:以客户端为基础的连接机制,客户端的 ServerTimeout 最好是 服务端 KeepAliveInterval 的两倍

2.所用到的机制: 重连机制,心跳机制

3.服务端代码:

Startup.cs 文件添加

public void ConfigureServices(IServiceCollection services)
        {
//添加SignalR应用
            services.AddSignalR(hubOptions =>
            {
                hubOptions.KeepAliveInterval = System.TimeSpan.FromSeconds(15);
            });
        }

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
        {
            //配置SignalR路由(注意:写在 app.UseMvc 前面)
            app.UseSignalR(route =>
            {
                route.MapHub<MessageHub>("/MessageHub");
            });
            app.UseMvc();
        }

建立HUB

  public class MessageHub : Hub<IMyClass>
    {
        private string GroupName = "MyGroupName";
        public override async Task OnConnectedAsync()
        {
            await Groups.AddToGroupAsync(Context.ConnectionId, GroupName);
            await base.OnConnectedAsync();
        }
        public override async Task OnDisconnectedAsync(Exception exception)
        {
            await Groups.RemoveFromGroupAsync(Context.ConnectionId, GroupName);
            await base.OnDisconnectedAsync(exception);
        }
        /// <summary>
        /// 服务端向客户端发送消息
        /// </summary>
        /// <param name="id"></param>
        /// <returns></returns>
        public async Task SendMessage(Guid id)
        {
            try
            {
                await Clients.Group(GroupName).TriggerEvent(id);
            }
            catch
            {

            }
        }
    }
    public interface IMyClass
    {
        //客户端定义的方法名也必须和这个方法名一样,包括签名.
        Task TriggerEvent(Guid id);
    }

建立MyHubController

[ApiController]
    public class MyHubController : ControllerBase
    {
        private readonly IHubContext<MessageHub, IMyClass> _hubContext;
        public SyncHubController(IHubContext<MessageHub, IMyClass> hubContext)
        {
            _hubContext = hubContext;
        }

        [HttpGet]
        [Route("api/MyHub/TriggerEvent")]
        public void TriggerEvent(Guid id)
        {
            try
            {
                _hubContext.Clients.All.TriggerEvent(id);
            }
            catch { }
        }
    }

4.客户端代码:

public class ClientSignalRClass
    {
        Guid id;
        HubConnection hubConnection;
        public ClientSignalRClass(Guid id)
        {
            this.id= id;
        }
        public async Task ConnectSignalRServerAsync()
        {
            hubConnection = new HubConnectionBuilder()
                            .WithUrl(ClientSignalRConfig.API_URL_Hub)
                            .WithAutomaticReconnect(new[] { TimeSpan.FromSeconds(0),TimeSpan.FromSeconds(2),TimeSpan.FromSeconds(5),TimeSpan.FromSeconds(10),TimeSpan.FromSeconds(30)
                            })
                            .Build();
            //连接服务超时时间
            hubConnection.ServerTimeout = TimeSpan.FromSeconds(30);
            //重连回调
            hubConnection.Reconnecting += hubConnection_Reconnecting;
            hubConnection.Reconnected += hubConnection_Reconnected;
            hubConnection.Closed += hubConnection_Closed;
            //TriggerClientSyncBalance事件名称与服务端一致
            hubConnection.On<Guid>("TriggerEvent", (x) => DoSomething(x));
            await StartConnection();
        }

        private async Task hubConnection_Closed(Exception arg)
        {
            try
            {
                await Task.Delay(TimeSpan.FromMilliseconds(1));
                LogHelper.WriteLog(string.Format("{0} {1}", "SignalR Closed:", arg.Message));
            }
            catch (Exception ex)
            {
                LogHelper.WriteLog(string.Format("{0} {1} {2}", "SignalR Reconnecting:", arg.Message, ex.Message));
            }
        }

        private async Task hubConnection_Reconnecting(Exception arg)
        {
            try
            {
                await Task.Delay(TimeSpan.FromMilliseconds(1));
                LogHelper.WriteLog(string.Format("{0} {1}", "SignalR Reconnecting:", arg.Message));
            }
            catch (Exception ex)
            {
                LogHelper.WriteLog(string.Format("{0} {1} {2}", "SignalR Reconnecting:", arg.Message, ex.Message));
            }
        }

        private async Task hubConnection_Reconnected(string arg)
        {
            try
            {
                await Task.Delay(TimeSpan.FromMilliseconds(1));
                LogHelper.WriteLog(string.Format("{0} {1}", "SignalR Reconnected:", arg));
            }
            catch (Exception ex)
            {
                LogHelper.WriteLog(string.Format("{0} {1} {2}", "SignalR Reconnected:", arg, ex.Message));
            }
        }

        private async Task StartConnection()
        {
            try
            {
                await hubConnection.StartAsync();
                LogHelper.WriteLog("SignalR 连接成功");
            }
            catch (Exception ex)
            {
                LogHelper.ErrorLog("SignalR 连接失败:", ex);
            }
        }
        private void DoSomething(Guid id)
        {
            //todo...
        }
    }