NetCore WebSocket即时通讯示例

public class MsgTemplate { public string SenderID { get; set; } public string ReceiverID { get; set; } public string MessageType { get; set; } public string Content { get; set; } }

public class ChatWebSocketMiddleware { private static ConcurrentDictionary<string, System.Net.WebSockets.WebSocket> _sockets = new ConcurrentDictionary<string, System.Net.WebSockets.WebSocket>(); private readonly RequestDelegate _next; public ChatWebSocketMiddleware(RequestDelegate next) {  _next = next; } public async Task Invoke(HttpContext context) {  if (!context.WebSockets.IsWebSocketRequest)  {  await _next.Invoke(context);  return;  }  System.Net.WebSockets.WebSocket dummy;  CancellationToken ct = context.RequestAborted;  var currentSocket = await context.WebSockets.AcceptWebSocketAsync();  //string socketId = Guid.NewGuid().ToString();  string socketId = context.Request.Query["sid"].ToString();  if (!_sockets.ContainsKey(socketId))  {  _sockets.TryAdd(socketId, currentSocket);  }  //_sockets.TryRemove(socketId, out dummy);  //_sockets.TryAdd(socketId, currentSocket);  while (true)  {  if (ct.IsCancellationRequested)  {   break;  }  string response = await ReceiveStringAsync(currentSocket, ct);  MsgTemplate msg = JsonConvert.DeserializeObject<MsgTemplate>(response);  if (string.IsNullOrEmpty(response))  {   if (currentSocket.State != WebSocketState.Open)   {   break;   }   continue;  }  foreach (var socket in _sockets)  {   if (socket.Value.State != WebSocketState.Open)   {   continue;   }   if (socket.Key == msg.ReceiverID || socket.Key == socketId)   {   await SendStringAsync(socket.Value, JsonConvert.SerializeObject(msg), ct);   }  }  }  //_sockets.TryRemove(socketId, out dummy);  await currentSocket.CloseAsync(WebSocketCloseStatus.NormalClosure, "Closing", ct);  currentSocket.Dispose(); } private static Task SendStringAsync(System.Net.WebSockets.WebSocket socket, string data, CancellationToken ct = default(CancellationToken)) {  var buffer = Encoding.UTF8.GetBytes(data);  var segment = new ArraySegment<byte>(buffer);  return socket.SendAsync(segment, WebSocketMessageType.Text, true, ct); } private static async Task<string> ReceiveStringAsync(System.Net.WebSockets.WebSocket socket, CancellationToken ct = default(CancellationToken)) {  var buffer = new ArraySegment<byte>(new byte[8192]);  using (var ms = new MemoryStream())  {  WebSocketReceiveResult result;  do  {   ct.ThrowIfCancellationRequested();   result = await socket.ReceiveAsync(buffer, ct);   ms.Write(buffer.Array, buffer.Offset, result.Count);  }  while (!result.EndOfMessage);  ms.Seek(0, SeekOrigin.Begin);  if (result.MessageType != WebSocketMessageType.Text)  {   return null;  }  using (var reader = new StreamReader(ms, Encoding.UTF8))  {   return await reader.ReadToEndAsync();  }  } } }

if (socket.Key == msg.ReceiverID || socket.Key == socketId){ await SendStringAsync(socket.Value,JsonConvert.SerializeObject(msg), ct);}

app.UseWebSockets();app.UseMiddleware<ChatWebSocketMiddleware>();

export class Dialog { private ws: any; private msgArr: Array<any>; constructor(private httpService: HttpService) { this.msgArr = []; } ionViewDidEnter() { if (!this.ws) {  this.ws = new WebSocket("ws://localhost:56892?sid=222");  this.ws.onopen = () => {  console.log('open');  };  this.ws.onmessage = (event) => {  console.log('new message: ' + event.data);  var msgObj = JSON.parse(event.data);  this.msgArr.push(msgObj);;  };  this.ws.onerror = () => {  console.log('error occurred!');  };  this.ws.onclose = (event) => {  console.log('close code=' + event.code);  }; } } sendMsg(msg) {//msg为我要发送的内容 比如"hello world" var msgObj = {  SenderID: "222",  ReceiverID: "111",  MessageType: "text",  Content: msg }; this.ws.send(JSON.stringify(msgObj)); }

<div class="container" style="width:90%;margin:0px auto;border:1px solid steelblue;"> <div class="msg"> <div id="msgs" style="height:200px;"></div> </div> <div style="display:block;width:100%"> <input type="text" style="max-width:unset;width:100%;max-width:100%" id="MessageField" placeholder="type message and press enter" /> </div></div>

<script> $(function () {  $('.navbar-default').addClass('on');  var userName = '@Model';  var protocol = location.protocol === "https:" ? "wss:" : "ws:";  var wsUri = protocol + "//" + window.location.host + "?sid=111";  var socket = new WebSocket(wsUri);  socket.onopen = e => {  console.log("socket opened", e);  };  socket.onclose = function (e) {  console.log("socket closed", e);  };  socket.onmessage = function (e) {  console.log(e);  var msgObj = JSON.parse(e.data);  $('#msgs').append(msgObj.Content + '<br />');  };  socket.onerror = function (e) {  console.error(e.data);  };  $('#MessageField').keypress(function (e) {  if (e.which != 13) {   return;  }  e.preventDefault();  var message = $('#MessageField').val();  var msgObj = {   SenderID:"111",   ReceiverID:"222",   MessageType: "text",   Content: message  };  socket.send(JSON.stringify(msgObj));  $('#MessageField').val('');  }); }); </script>