c# webapi websocket 服务端消息发送

Posted 2021-03-29 椎叶古杜音

参考网址
https://www.cnblogs.com/wangx036/p/12565128.html

WebSocket相当于在MvC中做了一个一直运行的服务 

将其他来源的数据接收

using System;using System.Collections.Generic;using System.Net;using System.Net.Http;using System.Net.WebSockets;using System.Text;using System.Threading;using System.Threading.Tasks;using System.Web;using System.Web.Http;using System.Web.WebSockets;using cxweb_pg.Models;
namespace cxweb_pg.Controllers{ public class WsChatController : ApiController { private static List<WebSocket> _sockets = new List<WebSocket>();  [HttpGet] public HttpResponseMessage Connect() { //在服务器端接受Web Socket请求，传入的函数作为Web Socket的处理函数， //待Web Socket建立后该函数会被调用，在该函数中可以对Web Socket进行消息收发 HttpContext.Current.AcceptWebSocketRequest(ProcessRequest);  //构造同意切换至Web Socket的Response. return Request.CreateResponse(HttpStatusCode.SwitchingProtocols);  }
 public async Task ProcessRequest(AspNetWebSocketContext context) { var socket = context.WebSocket;//传入的context中有当前的web socket对象 _sockets.Add(socket);//此处将web socket对象加入一个静态列表中
 //进入一个无限循环，当web socket close是循环结束 while (true) { var buffer = new ArraySegment<byte>(new byte[1024]); //对web socket进行异步接收数据 var receivedResult = await socket.ReceiveAsync(buffer, CancellationToken.None); if (receivedResult.MessageType == WebSocketMessageType.Close) { //如果client发起close请求，对client进行ack await socket.CloseAsync(WebSocketCloseStatus.Empty, string.Empty, CancellationToken.None); _sockets.Remove(socket); break; }
 if (socket.State == WebSocketState.Open) { string recvMsg = Encoding.UTF8.GetString(buffer.Array, 0, receivedResult.Count); var recvBytes = Encoding.UTF8.GetBytes(recvMsg); var sendBuffer = new ArraySegment<byte>(buffer.Array); //当接收到文本消息时，对当前服务器上所有web socket连接进行广播 foreach (var innerSocket in _sockets) { if (innerSocket != socket) { await innerSocket.SendAsync(sendBuffer, WebSocketMessageType.Text, true, CancellationToken.None); } } } } } }}

前端在使用的时候先调用Connect方法

然后在调用SendMsg方法来发送数据

     xxxController        private readonly ClientWebSocket webSocket = new ClientWebSocket(); private readonly CancellationToken _cancellation = new CancellationToken();

 [HttpPost] public async Task SendMsg(PostDataModel msg) { await webSocket.ConnectAsync(new Uri("ws://192.168.100.28:3030/zhzcapi/WsChat/Connect"), _cancellation); var sendBytes = Encoding.UTF8.GetBytes(msg.message);//发送的数据 var bsend = new ArraySegment<byte>(sendBytes); await webSocket.SendAsync(bsend, WebSocketMessageType.Binary, true, _cancellation); await webSocket.CloseAsync(WebSocketCloseStatus.NormalClosure, "1", _cancellation); webSocket.Dispose(); }

运行过程 Connect先运行的是建立了一个委托

该委托一直执行While内的循环直至连接关闭 (实际上是一直打开的 相当于保持该连接 不然会被清理)

每当有一个新消息SendMsg传过来时 向前端发送该消息