SignalR 应用实例

后台

using Microsoft.AspNetCore.Authorization;

using Microsoft.AspNetCore.SignalR;

using PaddypestChart.DataAccess.Core.IService.IAPP;

using System;

using System.Collections.Generic;

using System.Security.Claims;

using System.Threading.Tasks;

using Utility.src.Redis;

 

namespace Microsoft.AspNetCore.Builder

{

    /// <summary>

    /// 

    /// </summary>

    [Authorize]

    public class ChatHub : Hub

    {

        /// <summary>

        /// 

        /// </summary>

        private readonly object balanceLock = new object();

 

        /// <summary>

        /// 是否系统启动后第一次连接

        /// </summary>

        private static bool FirstConnected = true;

 

        /// <summary>

        /// 

        /// </summary>

        IOnline online;

 

        /// <summary>

        /// 

        /// </summary>

        ICommonUser commonUser;

 

        /// <summary>

        /// 构造函数

        /// </summary>

        /// <param name="online">服务注入</param>

        /// <param name="commonUser">服务注入</param>

        public ChatHub(IOnline online, ICommonUser commonUser)

        {

            this.online = online;

            this.commonUser = commonUser;

        }

 

        /// <summary>

        /// 向指定用户推送消息

        /// </summary>

        /// <param name="user"></param>

        /// <param name="message"></param>

        /// <returns></returns>

        public async Task SendMessage(string user, string message) => await Clients.User(user).SendAsync("ReceiveMessage", message);

 

        /// <summary>

        /// 连接触发

        /// </summary>

        /// <returns></returns>

        public override Task OnConnectedAsync()

        {

            if (FirstConnected)

            {

                //加锁，防止其它线程多次触发

                lock (balanceLock)

                {

                    if (FirstConnected)

                    {

                        //在线状态全设置成离线（记录数据保存在MSSQL）

                        online.SetOfflineOfAll();

                        FirstConnected = false;

                    }

                }

            }

            //设置在线状态，更改数据库中在线状态字段，1=在线，0=离线

            SetOnlineStatus(Context.ConnectionId, 1);

            //向管理员推送用户在线信息

            SendMessageAdmin();

            if(Context.UserIdentifier=="admin")

            {

                //从Redis中获取未推送消息（管理员离线未接收）

                var listRange = RedisHelper.ListRange<string>(Context.UserIdentifier) as List<string>;

                //遍历数据逐条推送

                foreach (var item in listRange)

                {

                    Clients.User("admin").SendAsync("UploadFilesMessage","", item);

                }

            }

            return base.OnConnectedAsync();

        }

 

        /// <summary>

        /// 连接断开触发

        /// </summary>

        /// <param name="exception"></param>

        /// <returns></returns>

        public override Task OnDisconnectedAsync(Exception exception)

        {

            SetOnlineStatus(Context.ConnectionId);

            SendMessageAdmin(0);

            return base.OnDisconnectedAsync(exception);

        }

 

        /// <summary>

        /// 加入组

        /// </summary>

        /// <param name="groupName"></param>

        /// <returns></returns>

        public async Task AddToGroup(string groupName)

        {

            await Groups.AddToGroupAsync(Context.ConnectionId, groupName);

 

            await Clients.Group(groupName).SendAsync("Send", $"{Context.ConnectionId} has joined the group {groupName}.");

        }

 

        /// <summary>

        /// 从组中删除

        /// </summary>

        /// <param name="groupName"></param>

        /// <returns></returns>

        public async Task RemoveFromGroup(string groupName)

        {

            await Groups.RemoveFromGroupAsync(Context.ConnectionId, groupName);

 

            await Clients.Group(groupName).SendAsync("Send", $"{Context.ConnectionId} has left the group {groupName}.");

        }

 

        /// <summary>

        /// 向管理员推送信息

        /// </summary>

        public async void SendMessageAdmin(int status = 1)

        {

            if (Context.UserIdentifier == "admin") return;

            var name = Context.User.FindFirstValue(ClaimTypes.GivenName);

            var statusstr = status == 1 ? "上线" : "下线";

            await Clients.User("admin").SendAsync("DynamicMessage", status, $"用户 {name} {statusstr}啦！");

        }

 

        /// <summary>

        /// 设置在线状态（保存至数据库）

        /// </summary>

        /// <param name="conneciionId"></param>

        /// <param name="status"></param>

        public void SetOnlineStatus(string conneciionId, int status = 0)

        {

            var appUser = commonUser.AppUserModebyLoginName(Context.UserIdentifier);

            online.SetOnlineStatus(appUser, conneciionId, status);

        }

 

        /// <summary>

        /// 客户端调用，表示信息已接收，数据从Redis中删除

        /// </summary>

        /// <param name="message"></param>

        public void CallBlack(string message)

        {

            RedisHelper.ListRemove("admin",message);

        }

 

    }

}

前端

//需要引用

//提示框插件

<script src="~/lib/toastr-2.1.4/toastr.min.js"></script>

//signalr必须

<script src="~/lib/signalr/dist/browser/signalr.js"></script>

 

"use strict";

let connection = new signalR.HubConnectionBuilder().withUrl("/chatHub").build();

 

//记录重连次数

let number = 0;

 

(function () { initializeToastr(); connectionStar();})();

 

//初始化toastr插件属性

function initializeToastr() {

    toastr.options = {

        progressBar: true,

        closeButton: false,

        debug: false,

        positionClass: "toast-bottom-right",

        onclick: null,

        showDuration: "300",

        hideDuration: "1000",

        timeOut: 5000,

        extendedTimeOut: 5000,

        showEasing: "swing",

        hideEasing: "linear",

        showMethod: "fadeIn",

        hideMethod: "fadeOut"

    };

}

 

function connectionStar() {

    initializeToastr();

    //开始连接

    connection.start().then(function () {

        if (number > 0) {

            //弹出提示框

            toastr.success("连接成功！");

            //连接成功，重置重连次数

            number = 0;

        }

    }).catch(function (err) {

        toastr.error("连接断开，正在重新连接(" + number + ")......");

        

        number++;

        //同步方法，等待执行完成

        setTimeout(() => connectionStar(), 5000);

    });

}

 

//接收推送消息

//function内参数，取决于后台中[await Clients.User("").SendAsync(method,status,message)]参数个数

//参数顺序一一对应

connection.on("DynamicMessage", function (status, message) {

    initializeToastr();

    //status 1=在线，2=离线

    if (status === 1)

        toastr.info(message);

    else

        toastr.info("<dev style='color:#C7C7C7'>" + message + "</dev>");

    //获取iframe对象

    let iframe = document.getElementById("J_iframe").contentWindow;

    //获取iframe打开的Url

    let url = iframe.location.href;

    //判断iframe打开的是否是OnlineUsers页面

    if (url.indexOf("OnlineUsers") >= 0)

        iframe.clientAjax();

});

 

//接收推送消息

connection.on("UploadFilesMessage", function (userId, message) {

    toastr.options.closeButton = true;

    toastr.options.timeOut = 20000;

    toastr.info(message);

    

    //想服务器推送消息，告知服务器消息已接收，"CallBlack"表示后台函数名

    connection.invoke("CallBlack", message).catch(function (err) {

        return toastr.error(err.toString());

    });

});

 

//连接断开触发

connection.onclose(function () {

    //重新连接

    setTimeout(() => connectionStar(), 5000);

});

 

signalR主要方法

JS

let connection = new signalR.HubConnectionBuilder().withUrl("/chatHub").build();

//连接

connection.start().then(function () {

    //连接成功操作

    ......

}).catch(function (err) {

    //连接失败操作

    ......

});

//接收推送

connection.on("method", function (userId, message) {

    ......

});

//发送消息

connection.invoke("method", message).catch(function (err) {

    //发送失败操作

    ......

});

//断开

connection.onclose(function () {

    ......

});

后台调用

/// <summary>

/// 连接触发

/// </summary>

/// <returns></returns>

public override Task OnConnectedAsync()

{

 

}

/// <summary>

/// 连接断开触发

/// </summary>

/// <param name="exception"></param>

/// <returns></returns>

public override Task OnDisconnectedAsync(Exception exception)

{

 

}

//消息推送

await Clients.User("").SendAsync(method,status,message);

 

其它类调用需要使用到注入

public void Test([FromServices]IHubContext<ChatHub> hubContext)

{

    hubContext.Clients.User(userId)

    .SendAsync(method, arg1, arg2);

}