消息推送SignalR

一、什么是 SignalR

　　ASP.NET SignalR is a library for ASP.NET developers that simplifies the process of adding real-time web functionality to applications. Real-time web functionality is the ability to have server code push content to connected clients instantly as it becomes available, rather than having the server wait for a client to request new data.

二、简单示例

　　新建项目 SignalRChat

　　选择 Empty 模板

　　安装 SignalR

　　添加完查看 Scripts 文件夹

　　添加 Signal Hub Class (V2)

　　代码如下

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using Microsoft.AspNet.SignalR;

namespace SignalRChat
{
    public class ChatHub : Hub
    {
        public void Send(string name, string message)
        {
            Clients.All.broadcastMessage(name, message);
        }
    }
}

　　添加 OWIN Startup class

　　代码如下

using System;
using System.Threading.Tasks;
using Microsoft.Owin;
using Owin;

[assembly: OwinStartup(typeof(SignalRChat.Startup))]

namespace SignalRChat
{
    public class Startup
    {
        public void Configuration(IAppBuilder app)
        {
            // For more information on how to configure your application, visit http://go.microsoft.com/fwlink/?LinkID=316888
            app.MapSignalR();
        }
    }
}

　　添加 HTML 页面

　　代码如下

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <title>SignalR Simple Chat</title>
    <style type="text/css">
        .container {
            background-color: #99CCFF;
            border: thick solid #808080;
            padding: 20px;
            margin: 20px;
        }
    </style>
</head>
<body>
    <div class="container">
        <input type="text" id="message" />
        <input type="button" id="sendmessage" value="Send" />
        <input type="hidden" id="displayname" />
        <ul id="discussion"></ul>
    </div>
    <!--Script references. -->
    <!--Reference the jQuery library. -->
    <script src="Scripts/jquery-1.6.4.min.js"></script>
    <!--Reference the SignalR library. -->
    <script src="Scripts/jquery.signalR-2.2.0.min.js"></script>
    <!--Reference the autogenerated SignalR hub script. -->
    <script src="signalr/hubs"></script>
    <!--Add script to update the page and send messages.-->
    <script type="text/javascript">
        $(function () {
            //To enable logging for your hub's events in a browser, add the following command to your client application
            $.connection.hub.logging = true;
            // Declare a proxy to reference the hub.
            var chat = $.connection.chatHub;
            // Create a function that the hub can call to broadcast messages.
            chat.client.broadcastMessage = function (name, message) {
                // Html encode display name and message.
                var encodedName = $('<div />').text(name).html();
                var encodedMsg = $('<div />').text(message).html();
                // Add the message to the page.
                $('#discussion').append('<li><strong>' + encodedName + '</strong>:&nbsp;&nbsp;' + encodedMsg + '</li>');
            };
            // Get the user name and store it to prepend to messages.
            $('#displayname').val(prompt('Enter your name:', ''));
            // Set initial focus to message input box.
            $('#message').focus();
            // Start the connection.
            $.connection.hub.start().done(function () {
                $('#sendmessage').click(function () {
                    // Call the Send method on the hub.
                    chat.server.send($('#displayname').val(), $('#message').val());
                    // Clear text box and reset focus for next comment.
                    $('#message').val('').focus();
                });
            });
        });
    </script>
</body>
</html>

　　F5 运行，复制 URL 再打开一个新浏览器窗口同时运行，分别输入 NameOne 和 NameTwo