CREATE TABLE [dbo].[tblUser]([UserId] [int] NOT NULL,[Name] [nvarchar](255) NOT NULL,[Email] [nvarchar](500) NOT NULL,[Mobile] [nvarchar](15) NOT NULL)
CREATE TABLE [dbo].[tblTask]([TaskId] [int] NOT NULL,[TaskCode] [nvarchar](50) NOT NULL,[TaskDate] [date] NULL,[AssignedTo] [int] NOT NULL,[Status] [nvarchar](50) NOT NULL,[Message] [nvarchar](500) NULL,[ReminderStart] [date] NOT NULL)
CREATE TABLE [dbo].[tblDailyReminder]([ReminderId] [int] IDENTITY(1,1) NOT NULL,[TaskId] [int] NOT NULL,[IsSent] [bit] NOT NULL CONSTRAINT [DF_tblDailyReminder_IsSent]  _DEFAULT ((0))
)

步骤2：创建一个存储过程

Create PROCEDURE [dbo].[sp_PushReminder]
AS
BEGIN                   Delete From tblDailyReminderInsert into tblDailyReminder(TaskId,IsSent)Select TaskId,0 from tblTask _where Status='Pending'and ReminderStart<=GETDATE()
END
Go

注意：我们必须启用代理服务才能使用SqlTableDependency。

USE master;
GO
ALTER DATABASE <Database_Name> SET ENABLE_BROKER WITH ROLLBACK IMMEDIATE;

步骤3：创建一个作业

[HubName("ReminderHub")]public class ReminderHub : Hub {private readonly ReminderClient _reminderClient;public ReminderHub() : this(ReminderClient.Instance) {}public ReminderHub(ReminderClient reminderClient) {_reminderClient = reminderClient;}}

步骤5：创建SignalR客户端

public class ReminderClient {private readonly static Lazy<ReminderClient> _instance = new Lazy<ReminderClient>(() => new ReminderClient(GlobalHost.ConnectionManager.GetHubContext<ReminderHub>().Clients));private static SqlTableDependency<tblDailyReminder> _sqltableDependency;public Dictionary<string, string> DictUsers = new Dictionary<string, string>();private ReminderClient(IHubConnectionContext<dynamic> clients) {Clients = clients;var mapper = new ModelToTableMapper<tblDailyReminder>();mapper.AddMapping(s => s.TaskId, "TaskId");mapper.AddMapping(s => s.ReminderId, "ReminderId");_ sqltableDependency = new SqlTableDependency<tblDailyReminder>(ConfigurationManager.ConnectionStrings["LocalConStr"].ConnectionString, "tblDailyReminder", "", mapper);_ sqltableDependency.OnChanged += SqlTableDependency_Changed;_ sqltableDependency.OnError += SqlTableDependency_OnError;_ sqltableDependency.Start();}public static ReminderClient Instance  {get {return _instance.Value;}}private IHubConnectionContext<dynamic> Clients {get;set;}void SqlTableDependency_OnError(object sender, ErrorEventArgs e) {throw e.Error;}void SqlTableDependency_Changed(object sender, RecordChangedEventArgs<tblDailyReminder> e) {if (e.ChangeType == ChangeType.Insert){NotificationDemoEntities notificationDemoEntities = new NotificationDemoEntities();var mailRecepients = notificationDemoEntities.tblDailyReminders.Where(x => x.ReminderId == e.Entity.ReminderId).Include(x => x.tblTask).Include(x => x.tblTask.tblUser).ToList();if (mailRecepients != null && mailRecepients.Count() > 0){SendMailNotification(mailRecepients.FirstOrDefault().tblTask.tblUser.Email, mailRecepients.FirstOrDefault().tblTask.Message);}}}private void SendMailNotification(string Tomail, string message)  {try{MailMessage mailMessage = new MailMessage();SmtpClient smtp = new SmtpClient();mailMessage.From = new MailAddress("FromMailAddress");mailMessage.To.Add(new MailAddress(Tomail));mailMessage.Subject = "Test";mailMessage.IsBodyHtml = true;mailMessage.Body = message;smtp.Port = 587;smtp.Host = "smtp.gmail.com";smtp.EnableSsl = true;smtp.UseDefaultCredentials = false;smtp.Credentials = new NetworkCredential("FromMailAddress", "password");smtp.DeliveryMethod = SmtpDeliveryMethod.Network;smtp.Send(mailMessage);}catch (Exception) {}}#region IDisposable Supportprivate bool disposedValue = false; // To detect redundant callsprotected virtual void Dispose(bool disposing) {if (!disposedValue) {if (disposing){_sqltableDependency.Stop();}disposedValue = true;}}~ReminderClient() {Dispose(false);}// This code added to correctly implement the disposable pattern.public void Dispose() {Dispose(true);GC.SuppressFinalize(this);}#endregion}

步骤6：在启动中注册SignalR

public class Startup{public void Configuration(IAppBuilder app)        {app.MapSignalR();}}

步骤7：创建集线器代理

protected void Application_Start(){AreaRegistration.RegisterAllAreas();FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);RouteConfig.RegisterRoutes(RouteTable.Routes);BundleConfig.RegisterBundles(BundleTable.Bundles);HubConnection hubConnection = new HubConnection("http://localhost:55027/signalr/hubs");hubProxy = hubConnection.CreateHubProxy("ReminderHub");hubConnection.Start();}

步骤9：测试应用