signalr - 如何使用 SignalR 制作服务器时间应用程序

Question

我倾向于 SignalR。如何编写一个简单的应用程序，以便用户可以使用 Hub 实时查看服务器时间。每隔 1 秒，服务器会将时间从服务器发送到连接的客户端

Answer 1

您可以在使用线程时执行此操作。

示例集线器类：

public class ServerTime : Hub
{
    public void Start()
    {
        Thread thread = new Thread(Write);
        thread.Start();
    }

    public void Write()
    {
        while (true)
        {
            Clients.settime(DateTime.Now.ToString());
            Thread.Sleep(1000);
        }
    }
}

示例脚本：

<script type="text/javascript">
    $(document).ready(function () {
        var time = $.connection.serverTime;
        $("#btnTest").click(function () {
            time.start();
        });

        time.settime = function (t) {
            $("#Time").html(t);
        };
        $.connection.hub.start();
    });
</script>
<div id="Time"></div>
<input id="btnTest" type="button" value="Test"/>

当您单击 btnTest 时，线程将开始工作。线程每秒向页面发送消息。

Answer 2

In Global.asax in the Application_Start(object sender, EventArgs e) method create a background thread and start it. In that thread you will need to do this to get access to your hub:

IConnectionManager connectionManager = AspNetHost.DependencyResolver
                                         .Resolve<IConnectionManager>();
dynamic clients = connectionManager.GetClients<ServerTime>();
clients.settime(DateTime.UtcNow.ToString());

NB DateTime.UtcNow is nearly always preferable since it doesn't leap around twice a year.

Answer 3

创建一个侦听器并在添加通知时引发一个事件:) 因此您不必不断检查数据库:)