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); 
 } 
} 

路由绑定：

[csharp] view plain copy
//绑定websocket 
app.Map("/ws", SocketHandler.Map); 

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总结