asp.net core webapi signalR通信

1.前端使用npm 导入signalR的包和jquery包
npm install jquery -y
npm install @micosoft/signalr -y

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>实时通讯</title><h1>signalr入门</h1>
</head>
<body><input type="button" value="发送" id="btnSend">
</body>
</html>
<script src="node_modules/jquery/dist/jquery.min.js"></script>
<script src="node_modules/@microsoft/signalr/dist/browser/signalr.min.js"></script>
<script>//创建连接对象var connection=new signalR.HubConnectionBuilder().withUrl("https://localhost:7177/myHub").build();
//当连接成功时
connection.start().then(function(){console.log("客户端连接成功");
})
//接收服务端主动推送过来的消息
connection.on("ReceiveMsg",function(msg){
alert(msg)
})
connection.on("completeOrder",function(msg){
alert(msg)
})
$("#btnSend").click(function(){
//客户端主动调用服务定义的通讯方法
connection.invoke("SendMsg",1,"测试").catch(function(err){
console.log(err)
})
})
</script>

后端–program中注入signalR的服务和跨域服务

 builder.Services.AddSignalR();//配置跨域builder.Services.AddCors(opt =>{opt.AddPolicy("ws.client", p =>{p.AllowCredentials();p.AllowAnyHeader();p.AllowAnyMethod();p.SetIsOriginAllowed(s => true);});});......app.MapHub<MyHub>("/myHub");app.UseCors("ws.client");

新建一个hub类

using Microsoft.AspNetCore.SignalR;
using Microsoft.Extensions.Caching.Memory;namespace WebApplication1.Hubs
{public class MyHub : Hub{private readonly IMemoryCache _memoryCache;public MyHub(IMemoryCache memoryCache){_memoryCache = memoryCache;}//当客户端成功连接时，会触发的方法public override Task OnConnectedAsync(){var cacheKey = "items_1";var cacheEntryOptions = new MemoryCacheEntryOptions().SetSlidingExpiration(TimeSpan.FromMinutes(30));_memoryCache.Set(cacheKey, Context.ConnectionId, cacheEntryOptions);return Task.CompletedTask;}//当客户端断开连接时,需要触发的方法public override Task OnDisconnectedAsync(Exception? exception){_memoryCache.Remove("items_1");return Task.CompletedTask;}public async void SendMsg(long userId, string msg){string sendMsg = $"服务端收到了客户端的消息,参数user={userId},msg={msg}";//服务端主动推送消息给所有的客户端//await Clients.All.SendAsync("ReceiveMsg", sendMsg);//给除了自己以外的所有客户端发送消息await Clients.Others.SendAsync("ReceiveMsg", sendMsg);}}
}

控制器类

using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.SignalR;
using Microsoft.Extensions.Caching.Memory;
using WebApplication1.Hubs;namespace WebApplication1.Controllers
{[ApiController][Route("[controller]/[action]")]public class WeatherForecastController : ControllerBase{private readonly IMemoryCache _memoryCache;private readonly IHubContext<MyHub> _hubContext;private static readonly string[] Summaries = new[]{"Freezing", "Bracing", "Chilly", "Cool", "Mild", "Warm", "Balmy", "Hot", "Sweltering", "Scorching"};private readonly ILogger<WeatherForecastController> _logger;public WeatherForecastController(ILogger<WeatherForecastController> logger, IMemoryCache memoryCache, IHubContext<MyHub> hubContext){_logger = logger;_memoryCache = memoryCache;_hubContext = hubContext;}[HttpGet(Name = "GetWeatherForecast")]public IEnumerable<WeatherForecast> Get(){return Enumerable.Range(1, 5).Select(index => new WeatherForecast{Date = DateTime.Now.AddDays(index),TemperatureC = Random.Shared.Next(-20, 55),Summary = Summaries[Random.Shared.Next(Summaries.Length)]}).ToArray();}[HttpPost]public void AddOrder(){var connectionId = _memoryCache.Get("items_1").ToString();//服务端向指定客户端发送信息。_hubContext.Clients.Client(connectionId).SendAsync("completeOrder", "订单完成");}}
}