SignalR

時間 2019-11-08

標籤 signalr 简体版

原文原文鏈接

1、理解SignalRjavascript

ASP .NET SignalR 是一個ASP .NET 下的類庫，能夠在ASP .NET 的Web項目中實現實時通訊（即：客戶端（Web頁面）和服務器端能夠互相實時的通知消息及調用方法），SignalR有三種傳輸模式：LongLooping(長輪詢)、WebSocket（HTML5的WEB套接字）、Forever Frame(隱藏框架的長請求鏈接)，能夠在WEB客戶端顯式指定一種或幾種，也能夠採起默認（推薦），若採起默認，SignalR會根據瀏覽器的環境自動選擇合適的傳輸方式。css

2、SignalR的三種實現方式html

第一種：採用集線器類（Hub）+非自動生成代理模式:服務端與客戶端分別定義的相對應的方法，客戶端經過代理對象調用服務端的方法，服務端經過IHubConnectionContext回調客戶端的方法，客戶端經過回調方法接收結果。java

以前我寫過一篇文章《分享一個基於長鏈接+長輪詢+原生的JS及AJAX實現的多人在線即時交流聊天室》，是經過長輪詢+長鏈接的方式來實現的在線多人聊天室功能，從代碼量來看就知道實現起來並不簡單，而現在有了SignalR，會簡單不少，我這裏使用SignalR再來寫一個簡單的在線多人聊天室示例，以便你們快速掌握SignalR。jquery

DEMO - 1 示例代碼以下：瀏覽器

服務端：服務器

//Startup類文件
 
using System;
using System.Threading.Tasks;
using Microsoft.Owin;
using Owin;
using Microsoft.AspNet.SignalR;
 
[assembly: OwinStartup(typeof(TestWebApp.Models.Startup))]
 
namespace TestWebApp.Models
{
    public class Startup
    {
        public void Configuration(IAppBuilder app)
        {
            app.MapSignalR();
        }
    }
}
 
 
//ChatHub類文件
 
using Microsoft.AspNet.SignalR;
using Microsoft.AspNet.SignalR.Hubs;
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using System.Web;
 
namespace TestWebApp.Models
{
    [HubName("chat")]
    public class ChatHub : Hub
    {
        public static ConcurrentDictionary<string, string> OnLineUsers = new ConcurrentDictionary<string, string>();
 
        [HubMethodName("send")]
        public void Send(string message)
        {
            string clientName = OnLineUsers[Context.ConnectionId];
            message = HttpUtility.HtmlEncode(message).Replace("\r\n", "<br/>").Replace("\n", "<br/>");
            Clients.All.receiveMessage(DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"), clientName, message);
        }
 
        [HubMethodName("sendOne")]
        public void Send(string toUserId, string message)
        {
            string clientName = OnLineUsers[Context.ConnectionId];
            message = HttpUtility.HtmlEncode(message).Replace("\r\n", "<br/>").Replace("\n", "<br/>");
            Clients.Caller.receiveMessage(DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"), string.Format("您對 {1}", clientName, OnLineUsers[toUserId]), message);
            Clients.Client(toUserId).receiveMessage(DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"), string.Format("{0} 對您", clientName), message);
        }
          
        public override System.Threading.Tasks.Task OnConnected()
        {
            string clientName = Context.QueryString["clientName"].ToString();
            OnLineUsers.AddOrUpdate(Context.ConnectionId, clientName, (key, value) => clientName);
            Clients.All.userChange(DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"), string.Format("{0} 加入了。", clientName), OnLineUsers.ToArray());
            return base.OnConnected();
        }
 
        public override System.Threading.Tasks.Task OnDisconnected(bool stopCalled)
        {
            string clientName = Context.QueryString["clientName"].ToString();
            Clients.All.userChange(DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"), string.Format("{0} 離開了。", clientName), OnLineUsers.ToArray());
            OnLineUsers.TryRemove(Context.ConnectionId, out clientName);
            return base.OnDisconnected(stopCalled);
        }
 
    }
}
 

public ActionResult Index()
{
    ViewBag.ClientName = "聊客-" + Guid.NewGuid().ToString("N");
    var onLineUserList = ChatHub.OnLineUsers.Select(u => new SelectListItem() { Text = u.Value, Value = u.Key }).ToList();
    onLineUserList.Insert(0, new SelectListItem() { Text = "-全部人-", Value = "" });
    ViewBag.OnLineUsers = onLineUserList;
    return View();
}

WEB客戶端：app

<!DOCTYPE html>
 
<html>
<head>
    <meta name="viewport" content="width=device-width" />
    <meta charset="utf-8" />
    <title>聊天室</title>
    <script src="~/Scripts/jquery-1.6.4.min.js" type="text/javascript"></script>
    <script src="~/Scripts/jquery.signalR-2.2.0.min.js" type="text/javascript"></script>
    <style type="text/css">
        #chatbox {
            width: 100%;
            height: 500px;
            border: 2px solid blue;
            padding: 5px;
            margin: 5px 0px;
            overflow-x: hidden;
            overflow-y: auto;
        }
 
        .linfo {
        }
 
        .rinfo {
            text-align: right;
        }
    </style>
    <script type="text/javascript">
        $(function () {
 
            var clientName = $("#clientname").val();
            var eChatBox = $("#chatbox");
            var eUsers = $("#users");
 
            var conn = $.hubConnection();
            conn.qs = { "clientName": clientName };
 
 
            conn.start().done(function () {
 
                $("#btnSend").click(function () {
                    var toUserId = eUsers.val();
                    if (toUserId != "") {
                        chat.invoke("sendOne", toUserId, $("#message").val())
                        .done(function () {
                            //alert("發送成功！");
                            $("#message").val("").focus();
                        })
                        .fail(function (e) {
                            alert(e);
                            $("#message").focus();
                        });
                    }
                    else {
                        chat.invoke("send", $("#message").val())
                        .done(function () {
                            //alert("發送成功！");
                            $("#message").val("").focus();
                        })
                        .fail(function (e) {
                            alert(e);
                            $("#message").focus();
                        });
                    }
                });
 
            });
 
            var chat = conn.createHubProxy("chat");
 
            chat.on("receiveMessage", function (dt, cn, msg) {
                var clsName = "linfo";
                if (cn == clientName || cn.indexOf("您對") >= 0) clsName = "rinfo";
                eChatBox.append("<p class='" + clsName + "'>" + dt + " <strong>" + cn + "</strong> 說：<br/>" + msg + "</p>");
                eChatBox.scrollTop(eChatBox[0].scrollHeight);
            });
 
            chat.on("userChange", function (dt, msg, users) {
                eChatBox.append("<p>" + dt + " " + msg + "</p>");
                eUsers.find("option[value!='']").remove();
                for (var i = 0; i < users.length; i++) {
                    if (users[i].Value == clientName) continue;
                    eUsers.append("<option value='" + users[i].Key + "'>" + users[i].Value + "</option>")
                }
            });
        });
    </script>
</head>
<body>
    <h3>大衆聊天室</h3>
    <div id="chatbox">
    </div>
    <div>
        <span>聊天名稱：</span>
        @Html.TextBox("clientname", ViewBag.ClientName as string, new { @readonly = "readonly", style = "width:300px;" })
        <span>聊天對象：</span>
        @Html.DropDownList("users", ViewBag.OnLineUsers as IEnumerable<SelectListItem>)
    </div>
    <div>
        @Html.TextArea("message", new { rows = 5, style = "width:500px;" })
        <input type="button" value="發送消息" id="btnSend" />
    </div>
</body>
</html>

服務端與客戶端代碼都比較簡單，網上相關的說明也有，這裏就再也不解說了，只說一下這種方式JS端調用服務端方法採用：chat.invoke，而被服務端回調的方法則採用：chat.on （這裏的chat是createHubProxy建立得來的）框架

第二種：採用集線器類（Hub）+自動生成代理模式ide

DEMO - 2 示例代碼以下：

服務端與DEMO 1相同，無需改變

客戶端：

<!DOCTYPE html>
 
<html>
<head>
    <meta name="viewport" content="width=device-width" />
    <meta charset="utf-8" />
    <title>聊天室</title>
    <script src="~/Scripts/jquery-1.6.4.min.js" type="text/javascript"></script>
    <script src="~/Scripts/jquery.signalR-2.2.0.min.js" type="text/javascript"></script>
    <script src="~/signalr/hubs" type="text/javascript"></script>
    <style type="text/css">
        #chatbox {
            width: 100%;
            height: 500px;
            border: 2px solid blue;
            padding: 5px;
            margin: 5px 0px;
            overflow-x: hidden;
            overflow-y: auto;
        }
 
        .linfo {
        }
 
        .rinfo {
            text-align: right;
        }
    </style>
    <script type="text/javascript">
        $(function () {
 
            var clientName = $("#clientname").val();
            var eChatBox = $("#chatbox");
            var eUsers = $("#users");
 
            var chat = $.connection.chat;
            $.connection.hub.qs = { "clientName": clientName };
            chat.state.test = "test";
 
            chat.client.receiveMessage = function (dt, cn, msg) {
                var clsName = "linfo";
                if (cn == clientName || cn.indexOf("您對")>=0) clsName = "rinfo";
                eChatBox.append("<p class='" + clsName + "'>" + dt + " <strong>" + cn + "</strong> 說：<br/>" + msg + "</p>");
                eChatBox.scrollTop(eChatBox[0].scrollHeight);
            }
 
            chat.client.userChange = function (dt, msg, users) {
                eChatBox.append("<p>" + dt + " " + msg + "</p>");
                eUsers.find("option[value!='']").remove();
                for (var i = 0; i < users.length; i++) {
                    if (users[i].Value == clientName) continue;
                    eUsers.append("<option value='" + users[i].Key + "'>" + users[i].Value + "</option>")
                }
            }
 
            $.connection.hub.start().done(function () {
 
                $("#btnSend").click(function () {
                    var toUserId = eUsers.val();
                    if (toUserId != "") {
                        chat.server.sendOne(toUserId, $("#message").val())
                            .done(function () {
                                //alert("發送成功！");
                                $("#message").val("").focus();
                            })
                            .fail(function (e) {
                                alert(e);
                                $("#message").focus();
                            });
                    }
                    else {
                        chat.server.send($("#message").val())
                        .done(function () {
                            //alert("發送成功！");
                            $("#message").val("").focus();
                        })
                        .fail(function (e) {
                            alert(e);
                            $("#message").focus();
                        });
                    }
                });
 
            });
 
        });
    </script>
</head>
<body>
    <h3>大衆聊天室</h3>
    <div id="chatbox">
    </div>
    <div>
        <span>聊天名稱：</span>
        @Html.TextBox("clientname", ViewBag.ClientName as string, new { @readonly = "readonly", style = "width:300px;" })
        <span>聊天對象：</span>
        @Html.DropDownList("users", ViewBag.OnLineUsers as IEnumerable<SelectListItem>)
    </div>
    <div>
        @Html.TextArea("message", new { rows = 5, style = "width:500px;" })
        <input type="button" value="發送消息" id="btnSend" />
    </div>
</body>
</html>

上述代碼中特別須要注意的是，須要引用一個「不存在的JS目錄」：<script src="~/signalr/hubs" type="text/javascript"></script>，爲何要打引號，是由於咱們在寫代碼的時候是不存在的，而當運行後就會自動生成signalr的代理腳本，這就是與非自動生成代理腳本最根本的區別，也正是由於這個自動生成的腳本，咱們能夠在JS中更加方便的調用服務端方法及定義回調方法，調用服務端方法採用：chat.server.XXX，而被服務端回調的客戶端方法則採用：chat.client.XXX

看一下上述兩種的運行效果截圖吧：

第三種：採用持久化鏈接類（PersistentConnection）

DEMO - 3 示例代碼以下：

服務端：

//Startup類：
 
using System;
using System.Threading.Tasks;
using Microsoft.Owin;
using Owin;
using Microsoft.AspNet.SignalR;
 
[assembly: OwinStartup(typeof(TestWebApp.Models.Startup))]
 
namespace TestWebApp.Models
{
    public class Startup
    {
        public void Configuration(IAppBuilder app)
        {
            app.MapSignalR<MyConnection>("/MyConnection");
        }
    }
}
 
 
//MyConnection類：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Web;
using Microsoft.AspNet.SignalR;
 
namespace TestWebApp.Models
{
    public class MyConnection : PersistentConnection
    {
        private static List<string> monitoringIdList = new List<string>();
        protected override Task OnConnected(IRequest request, string connectionId)
        {
            bool IsMonitoring = (request.QueryString["Monitoring"] ?? "").ToString() == "Y";
            if (IsMonitoring)
            {
                if (!monitoringIdList.Contains(connectionId))
                {
                    monitoringIdList.Add(connectionId);
                }
                return Connection.Send(connectionId, "ready");
            }
            else
            {
                if (monitoringIdList.Count > 0)
                {
                    return Connection.Send(monitoringIdList, "in_" + connectionId);
                }
                else
                {
                    return Connection.Send(connectionId, "nobody");
                }
            }
        }
 
        protected override Task OnReceived(IRequest request, string connectionId, string data)
        {
            if (monitoringIdList.Contains(connectionId))
            {
                return Connection.Send(data, "pass");
            }
            return null;
        }
 
        protected override Task OnDisconnected(IRequest request, string connectionId, bool stopCalled)
        {
            if (!monitoringIdList.Contains(connectionId))
            {
                return Connection.Send(monitoringIdList, "out_" + connectionId);
            }
            return null;
        }
    }
}

WEB客戶端：

<!-- MonitoringPage.cshtml 監控管理頁面-->
 
 
<!DOCTYPE html>
 
<html>
<head>
    <meta name="viewport" content="width=device-width" />
    <title>MonitoringPage</title>
    <script src="~/Scripts/jquery-1.6.4.min.js" type="text/javascript"></script>
    <script src="~/Scripts/jquery.signalR-2.2.0.min.js" type="text/javascript"></script>
    <style type="text/css">
        table {
            border:1px solid #808080;
            width:600px;
        }
        td {
            border:1px solid #808080;
            padding:3px;
        }
        .odd{ background-color: #bbf;}
        .even{ background-color:#ffc; }
        .non-temptr {
            display:none;
        }
    </style>
    <script type="text/javascript">
        $(function () {
            $("#userstable tbody tr:odd").addClass("odd");
            $("#userstable tbody tr:even").addClass("even");
 
            var conn = $.connection("/MyConnection", {"Monitoring":"Y"});
 
            conn.start().done(function () {
                $("#userstable").delegate("button.pass", "click", function () {
                    var rid = $(this).parent("td").prev().attr("data-rid");
                    conn.send(rid);
                    var tr = $(this).parents("tr");
                    tr.remove();
                });
                 
            }).fail(function (msg) {
                alert(msg);
            });
 
            conn.received(function (msg) {
                if (msg == "ready")
                {
                    $("#spstatus").html("監控服務已就緒");
                    return;
                }
                else if (msg.indexOf("in_") == 0) {
                    var tr = $(".non-temptr").clone(true);
                    tr.removeClass("non-temptr");
                    var td = tr.children().first();
                    var rid = msg.toString().substr("in_".length);
                    td.html(rid + "進入被監控頁面，是否容許？");
                    td.attr("data-rid", rid);
                    $("#userstable tbody").append(tr);
                }
                else
                {
                    var rid = msg.toString().substr("out_".length);
                    $("td[data-rid=" + rid + "]").parent("tr").remove();
                }
            });
 
        });
    </script>
</head>
<body>
    <div>
        如下是實時監控到進入EnterPage頁面的用戶狀況：(服務情況：<strong><span id="spstatus"></span></strong>)
    </div>
    <table id="userstable">
        <tr>
            <td>用戶進入消息</td>
            <td>授 權</td>
        </tr>
        <tr class="non-temptr">
            <td></td>
            <td style="width:100px"><button class="pass">容許</button></td>
        </tr>
    </table>
</body>
</html>
 
 
<!-- EnterPage.cshtml 監控受限頁面-->
<!DOCTYPE html>
 
<html>
<head>
    <meta name="viewport" content="width=device-width" />
    <title>EnterPage</title>
    <script src="~/Scripts/jquery-1.6.4.min.js" type="text/javascript"></script>
    <script src="~/Scripts/jquery.signalR-2.2.0.min.js" type="text/javascript"></script>
</head>
<body>
    <script type="text/javascript">
        $(function () {
            var conn = $.connection("/MyConnection");
 
            conn.start().fail(function (msg) {
                alert(msg);
            });
 
            conn.received(function (data) {
                if (data == "pass") {
                    $("#msg").html("管理員已審覈經過，能夠進入瀏覽詳情。");
                    setTimeout(function () {
                        self.location = "http://www.zuowenjun.cn";
                    }, 3000);
                }
                else
                {
                    $("#msg").html("無管理員在線，請稍候再從新進入該頁面。");
                }
            });
        });
    </script>
    <div id="msg">
        該頁面瀏覽受限，已自動將您的瀏覽請求發給管理員，請稍候。。。
    </div>
</body>
</html>

上述代碼能夠看出與採用Hub（集線器類）的不一樣之處，一是：Startup.Configuration中是須要指定app.MapSignalR<MyConnection>("/MyConnection")，二是需實現繼承自PersistentConnection類的自定義的持久化鏈接類，在這個鏈接中能夠重寫：OnConnected、OnDisconnected、OnReceived、OnReconnected、ProcessRequest方法，同時有幾個重要的屬性成員Connection、Groups，服務端發消息給客戶端採用：Connection.Broadcast（廣播，全部客戶端均可以收到消息）,Connection.Send（發送給指定的客戶端）

運行效果以下截圖示：

SignalR支持額外附加：QueryString、Cookie、State，具體的客戶端設置與服務端接收請見上面的代碼，同時也能夠參見以下其它博主總結的表格（SignalR的Javascript客戶端API使用方式整理）：

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