SqlDependency不点火

Question

我第一次尝试SqlDepenedency。我不会收到任何关于数据库更新的通知。

我在里面放置断点：OnChange(object sender, SqlNotificationEventArgs e)，

但它永远不会被击中。

这是我的代码：

    protected void Page_Load(object sender, EventArgs e)
    {

        Label1.Text = "Cache Refresh: " + DateTime.Now.ToLongTimeString();
        DateTime.Now.ToLongTimeString();
        // Create a dependency connection to the database.
        SqlDependency.Start(GetConnectionString());

        using (SqlConnection connection = new SqlConnection(GetConnectionString()))
        {
            using (SqlCommand command = new SqlCommand(GetSQL(), connection))
            {

                SqlDependency dependency =
                        new SqlDependency(command);

                    // Refresh the cache after the number of minutes
                    // listed below if a change does not occur.
                    // This value could be stored in a configuration file.
                                  connection.Open();

                dgHomeRequests.DataSource = command.ExecuteReader();
                    dgHomeRequests.DataBind();

            }
        }   
    }


    private string GetConnectionString()
    {
        // To avoid storing the connection string in your code,
        // you can retrieve it from a configuration file.
        //return "Data Source=(local);Integrated Security=true;" +"Initial Catalog=AdventureWorks;";
        return ConfigurationManager.ConnectionStrings["TestData"].ConnectionString;
    }
    private string GetSQL()
    {
        return "Select [Address] From [UserAccount1]";
    }


    void OnChange(object sender, SqlNotificationEventArgs e)
    {
        // have breakpoint here:
        SqlDependency dependency = sender as SqlDependency;

        // Notices are only a one shot deal
        // so remove the existing one so a new 
        // one can be added

        dependency.OnChange -= OnChange;

        // Fire the event
       /* if (OnNewMessage != null)
        {
            OnNewMessage();
        }*/
    }

我还在Global.asax文件中放置了一些代码：

public class Global : HttpApplication
{
    void Application_Start(object sender, EventArgs e)
    {
        // Code that runs on application startup
        RouteConfig.RegisterRoutes(RouteTable.Routes);
        BundleConfig.RegisterBundles(BundleTable.Bundles);
        SqlDependency.Start(ConfigurationManager.ConnectionStrings["TestData"].ConnectionString);
    }
    protected void Application_End()
    {
        // Shut down SignalR Dependencies
        SqlDependency.Stop(ConfigurationManager.ConnectionStrings["TestData"].ConnectionString);
    }
}

SQL服务器位于本地计算机上。我正在通过Visual (IIS Express)运行代码。

1. 若要在数据库上启用service，请执行以下操作： 更改数据库集ENABLE_BROKER GO
2. 要订阅查询通知，我们需要向IIS服务帐户授予权限。 将查询通知授予“”

我猜第二点是不需要的，因为它是本地的。但我试着给了它一些许可。不知道他们是否正确，因为我不认为它在使用应用程序pool.And不需要本地env的许可。如果我自己是用户并自己创建了模式。

我看到的一个问题是：

alter authorization on database::<dbName> to [sa];

我也同意了。

Answer 1

我错过了：dependency.OnChange += new OnChangeEventHandler(OnChange);新代码看起来像：

               SqlDependency dependency = new SqlDependency(command);

               dependency.OnChange += new OnChangeEventHandler(OnChange);

现在我可以解雇void OnChange(object sender, SqlNotificationEventArgs e)了