在ASP.NET CORE 2.0使用SignalR技术

一、前言

上次讲SignalR还是在《在ASP.NET Core下使用SignalR技术》文章中提到,ASP.NET Core 1.x.x 版本发布中并没有包含SignalR技术和开发计划中。时间过得很快,MS已经发布了.NET Core 2.0 Preview 2 预览版,距离正式版已经不远了,上文中也提到过在ASP.NET Core 2.0中的SignalR将做为重要的组件与MVC等框架一起发布。它的开发团队也兑现了承诺,使用TypeScript对它的javascript客户端进行重写,服务端方面也会贴近ASP.NET Core的开发方式,比如会集成到ASP.NET Core依赖注入框架中。

二、环境搭建

要在ASP.NET Core 2.0中使用SignalR,要先引用Microsoft.AspNetCore.SignalR 、 Microsoft.AspNetCore.SignalR.Http 两个Package包。

目前ASP.NET Core 2.0与SignalR还都是Preview版本,所以NUGET上也找不到SignalR的程序包,想添加引用我们就得去MyGet上去找找。既然要用MyGet的话,就要为项目添加NuGet源了。

1.添加NuGet源

在程序根目录新建一个命为NuGet.Config的文件内容如下:

<?xml version="1.0" encoding="utf-8"?>
<configuration>
    <packageSources>
        <clear/>
            <add key="aspnetcidev" value="https://dotnet.myget.org/F/aspnetcore-ci-dev/api/v3/index.json"/>
            <add key="api.nuget.org" value="https://api.nuget.org/v3/index.json"/>
    </packageSources>
</configuration>

2.编辑项目文件csproj

添加上面提到的两个包的引用:

    <PackageReference Include="Microsoft.AspNetCore.All" Version="2.0.0-preview3-26040" />
    <PackageReference Include="Microsoft.AspNetCore.SignalR" Version="1.0.0-preview3-26037" />
    <PackageReference Include="Microsoft.AspNetCore.SignalR.Http" Version="1.0.0-preview3-26037" />

我在这个示例里使用的是目前的最高,当然版本号每天都有可能发生变化,最新版本的SignalR,是不兼容.NET Core SDK 2.0 Preview 1中默认创建项目时Microsoft.AspNetCore.All这个包的版本的,这里也修改修改一下版本号为:Microsoft.AspNetCore.All 2.0.0-preview3-26040。

当然也可以用dotnet cli 来添加包引用:

dotnet add package Microsoft.AspNetCore.SignalR --version 1.0.0-preview3-26037 --source https://dotnet.myget.org/F/aspnetcore-dev/api/v3/index.json

dotnet add package Microsoft.AspNetCore.SignalR.Http --version 1.0.0-preview3-26037 --source https://dotnet.myget.org/F/aspnetcore-dev/api/v3/index.json

3.添加配置代码

我们需要在Startup类中的 ConfigureServices方法中添加如下代码:

public void ConfigureServices(IServiceCollection services)
{
    services.AddSignalR();
}

在Startup类中的Configure方法中添加如下代码:

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
    app.UseStaticFiles();
    app.UseSignalR(routes =>
    {
        routes.MapHub<Chat>("hubs");
    });
}

4.添加一个HUB类

public class Chat : Hub
{
    public override async Task OnConnectedAsync()
    {
        await Clients.All.InvokeAsync("Send", $"{Context.ConnectionId} joined");
    }

    public override async Task OnDisconnectedAsync(Exception ex)
    {
        await Clients.All.InvokeAsync("Send", $"{Context.ConnectionId} left");
    }

    public Task Send(string message)
    {
        return Clients.All.InvokeAsync("Send", $"{Context.ConnectionId}: {message}");
    }

    public Task SendToGroup(string groupName, string message)
    {
        return Clients.Group(groupName).InvokeAsync("Send", $"{Context.ConnectionId}@{groupName}: {message}");
    }

    public async Task JoinGroup(string groupName)
    {
        await Groups.AddAsync(Context.ConnectionId, groupName);

        await Clients.Group(groupName).InvokeAsync("Send", $"{Context.ConnectionId} joined {groupName}");
    }

    public async Task LeaveGroup(string groupName)
    {
        await Groups.RemoveAsync(Context.ConnectionId, groupName);

        await Clients.Group(groupName).InvokeAsync("Send", $"{Context.ConnectionId} left {groupName}");
    }

    public Task Echo(string message)
    {
        return Clients.Client(Context.ConnectionId).InvokeAsync("Send", $"{Context.ConnectionId}: {message}");
    }
}

5.客户端支持

  在wwwroot目录下创建一个名为chat.html的Html静态文件,内容如下:

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8" />
    <title></title>
</head>
<body>
    <h1 id="head1"></h1>
    <div>
        <select id="formatType">
            <option value="json">json</option>
            <option value="line">line</option>
        </select>

        <input type="button" id="connect" value="Connect" />
        <input type="button" id="disconnect" value="Disconnect" />
    </div>


    <h4>To Everybody</h4>
    <form class="form-inline">
        <div class="input-append">
            <input type="text" id="message-text" placeholder="Type a message, name or group" />
            <input type="button" id="broadcast" class="btn" value="Broadcast" />
            <input type="button" id="broadcast-exceptme" class="btn" value="Broadcast (All Except Me)" />
            <input type="button" id="join" class="btn" value="Enter Name" />
            <input type="button" id="join-group" class="btn" value="Join Group" />
            <input type="button" id="leave-group" class="btn" value="Leave Group" />
        </div>
    </form>

    <h4>To Me</h4>
    <form class="form-inline">
        <div class="input-append">
            <input type="text" id="me-message-text" placeholder="Type a message" />
            <input type="button" id="send" class="btn" value="Send to me" />
        </div>
    </form>

    <h4>Private Message</h4>
    <form class="form-inline">
        <div class="input-prepend input-append">
            <input type="text" name="private-message" id="private-message-text" placeholder="Type a message" />
            <input type="text" name="user" id="target" placeholder="Type a user or group name" />

            <input type="button" id="privatemsg" class="btn" value="Send to user" />
            <input type="button" id="groupmsg" class="btn" value="Send to group" />
        </div>
    </form>

    <ul id="message-list"></ul>
</body>
</html>
<script src="signalr-client.js"></script>
<script src="utils.js"></script>
<script>
var isConnected = false;
function invoke(connection, method, ...args) {
    if (!isConnected) {
        return;
    }
    var argsArray = Array.prototype.slice.call(arguments);
    connection.invoke.apply(connection, argsArray.slice(1))
            .then(result => {
                console.log("invocation completed successfully: " + (result === null ? '(null)' : result));

                if (result) {
                    addLine('message-list', result);
                }
            })
            .catch(err => {
                addLine('message-list', err, 'red');
            });
}

function getText(id) {
    return document.getElementById(id).value;
}

let transportType = signalR.TransportType[getParameterByName('transport')] || signalR.TransportType.WebSockets;

document.getElementById('head1').innerHTML = signalR.TransportType[transportType];

let connectButton = document.getElementById('connect');
let disconnectButton = document.getElementById('disconnect');
disconnectButton.disabled = true;
var connection;

click('connect', event => {
    connectButton.disabled = true;
    disconnectButton.disabled = false;
    let http = new signalR.HttpConnection(`http://${document.location.host}/hubs`, { transport: transportType });
    connection = new signalR.HubConnection(http);
    connection.on('Send', msg => {
        addLine('message-list', msg);
    });

    connection.onClosed = e => {
        if (e) {
            addLine('message-list', 'Connection closed with error: ' + e, 'red');
        }
        else {
            addLine('message-list', 'Disconnected', 'green');
        }
    }

    connection.start()
        .then(() => {
            isConnected = true;
            addLine('message-list', 'Connected successfully', 'green');
        })
        .catch(err => {
            addLine('message-list', err, 'red');
        });
});

click('disconnect', event => {
    connectButton.disabled = false;
    disconnectButton.disabled = true;
    connection.stop()
        .then(() => {
            isConnected = false;
        });
});

click('broadcast', event => {
    let data = getText('message-text');
    invoke(connection, 'Send', data);
});

click('join-group', event => {
    let groupName = getText('message-text');
    invoke(connection, 'JoinGroup', groupName);
});

click('leave-group', event => {
    let groupName = getText('message-text');
    invoke(connection, 'LeaveGroup', groupName);
});

click('groupmsg', event => {
    let groupName = getText('target');
    let message = getText('private-message-text');
    invoke(connection, 'SendToGroup', groupName, message);
});

click('send', event => {
    let data = getText('me-message-text');
    invoke(connection, 'Echo', data);
});

</script>

值得注意的是,你可能会发现,目前找不到signalr-client.js这个文件,它是怎么来的呢,有两种方式:
第1种是通过下载SignalR的源代码,找到Client-TS项目,对TypeScript进行编译可以得到。

第2种比较简单通过Npm可以在线获取:

npm install signalr-client --registry https://dotnet.myget.org/f/aspnetcore-ci-dev/npm/

三、最后

  附上一个可用的Demo:https://github.com/maxzhang1985/AspNetCore.SignalRDemo

  GitHub:https://github.com/maxzhang1985/YOYOFx 如果觉还可以请Star下, 欢迎一起交流。

  .NET Core 开源学习群:214741894

posted @ 2017-07-04 20:37 YOYOFx 阅读(...) 评论(...) 编辑 收藏