NetCore_signalR服务端

前提

本文不介绍关于SignalR的原理内容，比如如何实现的长连接，如何实现双工通信，如何实现向下兼容的通信等等

本文仅仅记录如何实现一个服务端

环境

• IDE ：visual Studio2022
• 环境：.net6 webApi程序
• 语言：C#10

nuget 包

没有引入其他包，因为是WebApi项目，所以默认的asp.net的包都引入了。

开始改造

Program 的main函数

 //增加SignalR的服务
 builder.Services.AddSignalR();

  //指定Hub的路径和处理类
  app.MapHub("/sr/warning_broadcast");

完整代码

using Demo_WarningMonitor.Api.Services;
using Demo_WarningMonitor.Api.SignalRHubs;
using Demo_WarningMonitor.Api.Workers;
using Microsoft.AspNetCore.SignalR;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting.WindowsServices;

namespace Demo_WarningMonitor.Api
{
    public class Program
    {
        public static void Main(string[] args)
        {
            var builder = WebApplication.CreateBuilder(args);
            IConfiguration configuration = builder.Configuration;

            var options = new WebApplicationOptions
            {
                Args = args,
                ContentRootPath = WindowsServiceHelpers.IsWindowsService()
                                    ? AppContext.BaseDirectory : default
            };

            // Add services to the container. 
            builder.Services.AddControllers();  
          
            builder.Services.AddSignalR();

            // Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckle
            builder.Services.AddEndpointsApiExplorer();
            builder.Services.AddSwaggerGen();
 
            var app = builder.Build();

            // Configure the HTTP request pipeline.
            //if (app.Environment.IsDevelopment())
            //{
            app.UseSwagger();
            app.UseSwaggerUI();
            //}

            app.UseStaticFiles();

            app.UseHttpsRedirection();

            app.UseAuthorization();


            app.MapControllers();

            #region SignalR
            app.MapHub("/sr/warning_broadcast"); 
            #endregion 
            app.Run();
        }
    }
}

WarningBroadcastHub

一个自己定义的Hub处理类，继承自Hub

引入命名空间

using Microsoft.AspNetCore.SignalR;

完整代码

using Microsoft.AspNetCore.SignalR;

namespace Demo_WarningMonitor.Api.SignalRHubs
{
    /// 

    /// 报警广播
    /// 
    public class WarningBroadcastHub : Hub
    { 
        private ILogger logger; 

        public WarningBroadcastHub(ILogger logger, IConfiguration configuration)
        {
            this.logger = logger; 
        }

        public async Task SendMessage(string user, string message)
        {
            try
            {
                await Clients.All.SendAsync("ReceiveMessage", user, message);
            }
            catch (Exception ex)
            {
                logger.LogError(ex,"发送消息出现异常");
            }
          
        }
    }
}

结束语

到此为止一个服务端就做完了，运行起来也是看不到任何效果的。那么如何才能看到效果呢，请看下一篇文章

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