Asp.Net Core中WebSocket绑定的方法详解

说明

Websocket是html5后的产物，对于asp.net core中也得到了支持，Asp.Net Core中WebScoket的操作使用基本上和Asp.net中相同，不同的是，绑定监听。

Asp.Net Core2.0默认已经支持WebSocket，不需要另外安装Nuget包。

通过对HttpContext中的WebSockets.AcceptWebSocketAsync方法，接受WebSocket请求；并返回WebScoket对象。

下面话不多说了，来一起看看详细的介绍吧。

一、示例1,

1.后台启动文件Startup的configure中绑定WebSocket的路由监听

public void Configure(IApplicationBuilder app, IHostingEnvironment env, IServiceProvider svp) { ......  //绑定WebSocket  app.Map("/wsone/Connect", (con) =>  {   con.UseWebSockets();   WSHanleTwo _two = new WSHanleTwo();   con.Use(_two.Connect);  }); } 

2.定义请求处理类

using System.Net.WebSockets; using System.Threading; using System.Threading.Tasks; namespace Core_Razor_2 {  public class WSHanleTwo  {   private WebSocket socket = null;   //创建链接   public async Task Connect(HttpContext context, Func<Task> n)   {    try    {     //执行接收     WebSocket socket = await context.WebSockets.AcceptWebSocketAsync();     this.socket = socket;     //执行监听     await EchoLoop();    }    catch (Exception ex)    {     throw ex;    }   }   /// <summary>   /// 响应处理   /// </summary>   /// <returns></returns>   async Task EchoLoop()   {    var buffer = new byte[1024];    var seg = new ArraySegment<byte>(buffer);    while (this.socket.State == WebSocketState.Open)    {     var incoming = await this.socket.ReceiveAsync(seg, CancellationToken.None);     byte[] backInfo = System.Text.UTF8Encoding.Default.GetBytes("服务端相应内容");     var outgoing = new ArraySegment<byte>(backInfo, 0, incoming.Count);     await this.socket.SendAsync(outgoing, WebSocketMessageType.Text, true, CancellationToken.None);    }   }  } } 

3.前台请求代码

var socket; //var uri = "ws://" + window.location.host + "/ws"; var uri = "ws://" + window.location.host + "@Url.Action("Connect")"; var output; var text = "test echo"; function write(s) {  var p = document.createElement("p");  p.innerHTML = s;  output.appendChild(p); } function doConnect() {  socket = new WebSocket(uri);  socket.onopen = function (e) { write("opened " + uri); doSend(); };  socket.onclose = function (e) { write("closed"); };  socket.onmessage = function (e) { write("Received: " + e.data); socket.close(); };  socket.onerror = function (e) { write("Error: " + e.data); }; } function doSend() {  write("Sending: " + text);  socket.send(text); } function onInit() {  output = document.getElementById("output");  doConnect(); } window.onload = onInit; 

二、为了简单绑定，可以这样封装

public class SocketHandler {  public const int BufferSize = 4096;  WebSocket socket;  SocketHandler(WebSocket socket)  {   this.socket = socket;  }  async Task EchoLoop()  {   var buffer = new byte[BufferSize];   var seg = new ArraySegment<byte>(buffer);   while (this.socket.State == WebSocketState.Open)   {    var incoming = await this.socket.ReceiveAsync(seg, CancellationToken.None);    var outgoing = new ArraySegment<byte>(buffer, 0, incoming.Count);    await this.socket.SendAsync(outgoing, WebSocketMessageType.Text, true, CancellationToken.None);   }  }  static async Task Acceptor(HttpContext hc, Func<Task> n)  {   if (!hc.WebSockets.IsWebSocketRequest)    return;   var socket = await hc.WebSockets.AcceptWebSocketAsync();   var h = new SocketHandler(socket);   await h.EchoLoop();  }  /// <summary>  /// 路由绑定处理  /// </summary>  /// <param name="app"></param>  public static void Map(IApplicationBuilder app)  {   app.UseWebSockets();   app.Use(SocketHandler.Acceptor);  } }