SignalR SqlDependency Update 工作，但在更改页面时停止工作

您好，感谢您阅读本文。

使用本指南作为我的基础，我只添加了 Owin 登录/注册（cookie）

当我登录时，它会显示来自我的通知中心的通知，并且我能够更新数据库并立即运行更新。因此，在您尝试切换页面之前，一切正常，然后通知停止。即使我只是更新当前页面。

可能是什么问题？

using System;
using System.Collections.Generic;
using System.Configuration;
using System.Data;
using System.Data.SqlClient;
using System.Linq;
using System.Web;
using System.Threading.Tasks;
using Microsoft.AspNet.SignalR;
using Microsoft.AspNet.SignalR.Hubs;
using System.Security.Claims;
using System.Collections.Concurrent;
namespace LifeChange
{
[HubName("notificationHub")]
public class NotificationHub : Hub
{
    private static readonly ConcurrentDictionary<string, User> Users = new ConcurrentDictionary<string, User>(StringComparer.InvariantCultureIgnoreCase);
    private static List<User> UserList = new List<User>();
    Int16 totalNewMessages = 0;
    string UserID;
    [HubMethodName("check")]
    public Task Check(string id)
    {
        if (!Users.ToList().Exists(i => i.Value.ProfileId == id))
        {
            string profileId = id; //Context.QueryString["id"];
            string connectionId = Context.ConnectionId;
            var user = Users.GetOrAdd(profileId, _ => new User
            {
                ProfileId = profileId,
                ConnectionIds = connectionId
            });
            lock (user.ConnectionIds)
            {
                Groups.Add(connectionId, user.ProfileId);
            }
            return base.OnConnected();
        }
        return null;
    }
    [HubMethodName("sendNotifications")]
    public Task SendNotifications(string id)
    {
        UserID = id;
        using (var connection = new SqlConnection(ConfigurationManager.ConnectionStrings["DefaultConnection"].ConnectionString))
        {
            string query = "SELECT NotificationNumber FROM [dbo].[NotificationStatus] WHERE UserID=" + UserID;
            connection.Open();
            using (SqlCommand command = new SqlCommand(query, connection))
            {
                command.Notification = null;
                DataTable dt = new DataTable();
                SqlDependency dependency = new SqlDependency(command);
                dependency.OnChange += new OnChangeEventHandler(dependency_OnChange);
                if (connection.State == ConnectionState.Closed)
                    connection.Open();
                var reader = command.ExecuteReader();
                dt.Load(reader);
                if (dt.Rows.Count > 0)
                {
                    totalNewMessages = Int16.Parse(dt.Rows[0]["NotificationNumber"].ToString());
                }
            }
        }
        IHubContext context = GlobalHost.ConnectionManager.GetHubContext<NotificationHub>();
        //return context.Clients.All.RecieveNotification(totalNewMessages);
        return context.Clients.Client(Users.Values.FirstOrDefault(i => i.ProfileId == UserID).ConnectionIds).RecieveNotification(totalNewMessages);
    }
    private void dependency_OnChange(object sender, SqlNotificationEventArgs e)
    {
        if (e.Type == SqlNotificationType.Change)
        {
            NotificationHub nHub = new NotificationHub();
            nHub.SendNotifications(UserID);
        }
    }
}
}