NetCore WebSocket 即时通讯示例

1.新建Netcore Web项目

2.创建简易通讯协议

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

SenderID发送者ID

ReceiverID 接受者ID

MessageType 消息类型  Text  Voice 等等

Content 消息内容

3.添加中间件ChatWebSocketMiddleware

 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[]);
             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(, SeekOrigin.Begin);
                 if (result.MessageType != WebSocketMessageType.Text)
                 {
                     return null;
                 }

                 using (var reader = new StreamReader(ms, Encoding.UTF8))
                 {
                     return await reader.ReadToEndAsync();
                 }
             }
         }
     }

控制只有接收者才能收到消息
if (socket.Key == msg.ReceiverID || socket.Key == socketId)
{
     await SendStringAsync(socket.Value,JsonConvert.SerializeObject(msg), ct);
}

4.在Startup.cs中使用中间件

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

5.建立移动端测试示例 这里采用Ionic3运行在web端

创建ionic3项目略过 新手可点这里查看  或者有Angular2/4项目经验的可直接往下看

(1) 启动Ionic项目

当初创建ionic3项目时候遇到不少问题

比如ionic-cli初始化项目失败 切换到默认npmorg源就好了

比如ionic serve失败 打开代理允许*就好了

启动后界面是这样式的

(2) 创建聊天窗口dialog  具体布局实现 模块加载略过 直接进入websocket实现

在这之前别忘了启动web项目 否则会出现这样情况 链接不到服务

(3)dialog.ts具体实现

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: "",
            ReceiverID: "",
            MessageType: "text",
            Content: msg
        };
        this.ws.send(JSON.stringify(msgObj));
    }

ws://localhost:56892?sid=222 这是websocke服务链接地址

sid表示着我这个端的WebSocke唯一标识  找到这个key就可以找到我这个用户端了

6.在web端也实现一个会话窗口

<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 != ) {
                    return;
                }

                e.preventDefault();

                var message = $('#MessageField').val();

                var msgObj = {
                    SenderID:"",
                    ReceiverID:"",
                    MessageType: "text",
                    Content: message
                };
                socket.send(JSON.stringify(msgObj));
                $('#MessageField').val('');
            });
        });
    </script>

基本开发完成 接下来看看效果

7.web和webapp端对话

8.webapp发送  web接收

9.目前就实现了这么多  因为项目还涉及其它技术 暂时不开放源码了