我可以在我的网站信息中心上显示实时行更新。但是，当尝试使用通知几乎完全相同时，我的onchange事件只会触发一次。 Signalboard连接正由仪表板更新使用，它可以100％的时间工作。所有代码几乎完全相同，除了我每次都在仪表板上获取每一行，并且在获取数据库后不对数据库进行任何更新。
这就是我想要做的事情。
这是我第一次或任何时候刷新浏览器，但SQLDependency onchange在此之后再次触发或者根本不再触发。
$(document).ready(function ( $ ) {
var notificationHub = $.connection.notyHub;
notificationHub.client.showNotification = function () {
getNotifications();
markSet();
};
$.connection.hub.start();
getNotifications();
});
function getNotifications() {
$.ajax({
url: '../Notification/GetNotifications',
type: 'GET',
global: false,
datatype: 'json',
success: function (data) {
if (data.length > 0) {
for (var i = 0; i < data.length; i++) {
noty({
text: data[i].NotificationText,
type: 'information',
timeout: 0,
closeWith: ['hover'],
maxVisible: 1
});
markSent(data[i].ID);
}
}
}
});
}
function markSent(id) {
$.ajax({
url: '../Notification/MarkNotificationSent',
type: 'POST',
data: JSON.stringify({ notyID: id }),
dataType: 'json',
contentType: 'application/json',
global: false,
error: function (req, status, error) {
alert("R: " + req + " S: " + status + " E: " + error);
}
});
}
public class NotificationController : CaseEnhancedController
{
private readonly NotificationRepository notyRepo = new NotificationRepository();
private ReaderWriterLockSlim methodLock = new ReaderWriterLockSlim();
[OutputCache(Duration = 0)]
public JsonResult GetNotifications()
{
try
{
methodLock.EnterWriteLock();
IEnumerable<Notification> notifications = notyRepo.GetData();
JsonResult notysJSon = new JsonResult();
notysJSon.JsonRequestBehavior = JsonRequestBehavior.AllowGet;
notysJSon.Data = notifications;
return notysJSon;
}
catch (Exception ex)
{
throw ex;
}
finally
{
if (methodLock.IsWriteLockHeld)
methodLock.ExitWriteLock();
}
}
[HttpPost]
public JsonResult MarkNotificationSent(string notyID)
{
string sConn = "Integrated Security=SSPI;Persist Security Info=False;Initial Catalog=SirenCMNew;Data Source=localhost";
try
{
methodLock.EnterWriteLock();
using (SqlConnection connection = new SqlConnection(sConn))
{
if (connection.State == ConnectionState.Closed)
connection.Open();
using (SqlCommand cmd = new SqlCommand("[dbo].[spMarkNotificationSent]", connection))
{
cmd.CommandType = CommandType.StoredProcedure;
SqlParameter idParm = new SqlParameter
{
Value = notyID,
SqlDbType = SqlDbType.BigInt,
ParameterName = "ID"
};
cmd.Parameters.Add(idParm);
cmd.ExecuteNonQuery();
}
}
return Json(new { result = notyID }, JsonRequestBehavior.AllowGet);
}
catch (Exception ex)
{
return Json(new { result = 0 }, JsonRequestBehavior.AllowGet);
}
finally
{
if (methodLock.IsWriteLockHeld)
methodLock.ExitWriteLock();
}
}
public class NotificationRepository
{
string sConn = "Integrated Security=SSPI;Persist Security Info=False;Initial Catalog=SirenCMNew;Data Source=localhost";
public IEnumerable<Notification> GetData()
{
try
{
using (var connection = new SqlConnection(sConn))
{
connection.Open();
using (SqlCommand command = new SqlCommand(@"EXEC [dbo].[spGetUnsentNotifications]", connection))
{
command.Notification = null;
SqlDependency dependency = new SqlDependency(command);
dependency.OnChange += new OnChangeEventHandler(OnChange);
if (connection.State == ConnectionState.Closed)
connection.Open();
using (var reader = command.ExecuteReader())
return reader.Cast<IDataRecord>()
.Select(x => new Notification()
{
ID = x.GetInt64(0),
NotificationText = x.GetString(1)
}).ToList();
}
}
}
catch (Exception ex)
{
throw ex;
}
}
private void OnChange(object sender, SqlNotificationEventArgs e)
{
SqlDependency dependency = sender as SqlDependency;
dependency.OnChange -= OnChange;
if (e.Info == SqlNotificationInfo.Insert)
{
NotificationHub.Show();
}
}
[HubName("notyHub")]
public class NotificationHub : Hub
{
public static void Show()
{
IHubContext context = GlobalHost.ConnectionManager.GetHubContext<JobInfoHub>();
context.Clients.All.showNotification();
}
}
CREATE PROCEDURE [dbo].[spGetUnsentNotifications]
AS
SELECT
ID, NotificationText
FROM
dbo.SystemNotifications
WHERE
Sent = 0
GO
CREATE PROCEDURE dbo.spMarkNotificationSent
@ID bigint
AS
UPDATE
dbo.SystemNotifications
SET
Sent = 1
WHERE
ID = @ID
答案 0 :(得分：0)
我终于弄明白了。我不得不采取不同的方法。这就是我做的方式
if (e.Info == SqlNotificationInfo.Insert)
{
id = GetLastRecord();
}
if (id != 0)
DeleteNotification(id);
GetData();
}
private long GetLastRecord()
{
Notification notification = null;
long id = 0;
try
{
using (var connection = new SqlConnection(sConn))
{
connection.Open();
using (SqlCommand command = new SqlCommand(@"SELECT TOP 1 ID, NotificationText FROM dbo.SystemNotifications with(nolock)", connection))
{
if (connection.State == ConnectionState.Closed)
connection.Open();
using (var reader = command.ExecuteReader())
{
while (reader.Read())
{
notification = new Notification
{
ID = (long)reader.GetSqlInt64(0)
, NotificationText = reader.GetString(1)
};
}
}
if (null != notification)
{
NotificationHub.Show(notification);
id = notification.ID;
}
return id;
}
}
}
catch (Exception ex)
{
throw ex;
}
}
private static void DeleteNotification(long notyID)
{
string sConn = "Integrated Security=SSPI;Persist Security Info=False;Initial Catalog=SirenCMNew;Data Source=localhost";
try
{
using (SqlConnection connection = new SqlConnection(sConn))
{
if (connection.State == ConnectionState.Closed)
connection.Open();
using (SqlCommand cmd = new SqlCommand("[dbo].[spDeleteNotification]", connection))
{
cmd.CommandType = CommandType.StoredProcedure;
SqlParameter idParm = new SqlParameter
{
Value = notyID,
SqlDbType = SqlDbType.BigInt,
ParameterName = "ID"
};
cmd.Parameters.Add(idParm);
cmd.ExecuteNonQuery();
}
}
}
catch (Exception ex)
{
//TODO
}
}
[HubName("notyHub")]
public class NotificationHub : Hub
{
public static void Show(Notification notification)
{
IHubContext context = GlobalHost.ConnectionManager.GetHubContext<NotificationHub>();
context.Clients.All.showNoty(notification.ID, notification.NotificationText);
}
}
public class NotificationController : CaseEnhancedController
{
private readonly NotificationRepository notyRepo = new NotificationRepository();
private ReaderWriterLockSlim methodLock = new ReaderWriterLockSlim();
[OutputCache(Duration = 0)]
public JsonResult GetNotifications()
{
int count = 0;
try
{
methodLock.EnterWriteLock();
IEnumerable<Notification> notifications = notyRepo.GetData();
count = notifications.Count();
JsonResult notysJSon = new JsonResult();
notysJSon.JsonRequestBehavior = JsonRequestBehavior.AllowGet;
notysJSon.Data = notifications;
return notysJSon;
}
catch (Exception ex)
{
throw ex;
}
finally
{
if (methodLock.IsWriteLockHeld)
methodLock.ExitWriteLock();
if (count > 0)
DeleteNotifications();
}
}
private static void DeleteNotifications()
{
string sConn = "Integrated Security=SSPI;Persist Security Info=False;Initial Catalog=SirenCMNew;Data Source=localhost";
try
{
using (SqlConnection connection = new SqlConnection(sConn))
{
if (connection.State == ConnectionState.Closed)
connection.Open();
using (SqlCommand cmd = new SqlCommand("[dbo].[spDeleteAllNotifications]", connection))
{
cmd.CommandType = CommandType.StoredProcedure;
cmd.ExecuteNonQuery();
}
}
}
catch (Exception ex)
{
//TODO
}
}
$(function () {
var notificationHub = $.connection.notyHub;
notificationHub.client.showNoty = function (id, message) {
showNotification(id, message);
};
$.connection.hub.start();
getNotifications();
}
function showNotification(id, message)
{
noty({
text: message,
type: 'information',
timeout: 0,
closeWith: ['hover'],
maxVisible: 1
});
}
function getNotifications() {
$.ajax({
url: '../Notification/GetNotifications',
type: 'GET',
global: false,
datatype: 'json',
success: function (data) {
if (data.length > 0) {
for (var i = 0; i < data.length; i++) {
showNotification(data[i].ID, data[i].NotificationText);
}
}
}
});
}
答案 1 :(得分：0)
您应该将以下方法编写为＆＃39; e sp：
CREATE PROCEDURE [dbo].[spGetUnsentNotifications]
AS
SELECT
[ID], [NotificationText]
FROM
[dbo].[SystemNotifications]
WHERE
[Sent] = 0
GO
CREATE PROCEDURE [dbo].[spMarkNotificationSent]
@ID bigint
AS
UPDATE
[dbo].[SystemNotifications]
SET [Sent] = 1
WHERE [ID] = @ID