Install-Package Microsoft.AspNet.SignalR

using Microsoft.Owin;
using Owin;
[assembly: OwinStartup(typeof(RealTimeDataUpdate.Startup))]
namespace RealTimeDataUpdate
{
    public class Startup
    {
        public void Configuration(IAppBuilder app)
        {
            app.MapSignalR();
        }
    }
}

using System.Data.Entity;
public class DataContext : DbContext
{
    public DbSet<SensorData> SensorData { get; set; }
}
public class SensorData
{
    public int Id { get; set; }
    public string Temperature { get; set; }
    public string Humidity { get; set; }
    public DateTime Timestamp { get; set; }
}

<connectionStrings>
    <add name="DataContext" connectionString="Data Source=(localdb)\MSSQLLocalDB;Initial Catalog=RealTimeData;Integrated Security=True" providerName="System.Data.SqlClient" />
</connectionStrings>

using Microsoft.AspNet.SignalR;
public class DataHub : Hub
{
    public void SendData(string temperature, string humidity)
    {
        Clients.All.updateData(new { Temperature = temperature, Humidity = humidity, Timestamp = DateTime.Now });
    }
}

using System;
using System.Threading;
public class DataScheduler
{
    private Timer _timer;
    public void Start()
    {
        _timer = new Timer(UpdateData, null, 0, 5000); // 每5秒執(zhí)行一次
    }
    private void UpdateData(object state)
    {
        using (var context = new DataContext())
        {
            var latestData = context.SensorData.OrderByDescending(d => d.Timestamp).FirstOrDefault();
            if (latestData != null)
            {
                var hubContext = GlobalHost.ConnectionManager.GetHubContext<DataHub>();
                hubContext.Clients.All.updateData(new
                {
                    Temperature = latestData.Temperature,
                    Humidity = latestData.Humidity,
                    Timestamp = latestData.Timestamp
                });
            }
        }
    }
}

protected void Application_Start()
{
    AreaRegistration.RegisterAllAreas();
    FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
    RouteConfig.RegisterRoutes(RouteTable.Routes);
    BundleConfig.RegisterBundles(BundleTable.Bundles);
    var scheduler = new DataScheduler();
    scheduler.Start();
}

@model IEnumerable<RealTimeDataUpdate.Models.SensorData>
@{
    ViewBag.Title = "實時數據監(jiān)測";
}
<h2>最新溫濕度數據</h2>
<table>
    <tr>
        <th>Temperature</th>
        <th>Humidity</th>
        <th>Timestamp</th>
    </tr>
    <tr>
        <td id="temperature"></td>
        <td id="humidity"></td>
        <td id="timestamp"></td>
    </tr>
</table>
<script src="~/Scripts/jquery-3.6.0.min.js"></script>
<script src="~/Scripts/jquery.signalR-2.4.2.min.js"></script>
<script src="~/signalr/hubs"></script>
<script type="text/javascript">
    $(document).ready(function() {
        var hub = $.connection.dataHub;
        hub.client.updateData = function (data) {
            $('#temperature').text(data.Temperature);
            $('#humidity').text(data.Humidity);
            $('#timestamp').text(data.Timestamp);
        };
        $.connection.hub.start().done(function () {
            console.log("SignalR connected");
        });
    });
</script>