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[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();
                }
            }
        }
    }

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 打开代理允许翻墙就好了

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: "222",
            ReceiverID: "111",
            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="90%;margin:0px auto;border:1px solid steelblue;">
    <div class="msg">
        <div id="msgs" style="height:200px;"></div>
    </div>

    <div style="display:block;100%">
        <input type="text" style="max-unset;100%;max-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>

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