Question

我第一次尝试SqlDepenedency。我没有收到有关数据库更新的任何通知。

我在内部放置断点： 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 Server位于本地计算机上。我通过Visual Studio（IIS Express）运行代码。

在数据库上启用服务代理：

ALTER DATABASE SET ENABLE_BROKER GO
要订阅查询通知，我们需要授予IIS服务帐户
的权限
```
GRANT SUBSCRIBE QUERY NOTIFICATIONS TO “<serviceAccount>”
```

我猜测第二点不是必需的，因为它是本地的。但我尝试给它一些权限。不知道他们是否正确，因为我认为它不使用app pool。并且不需要本地环境的许可。如果我自己是用户并自己创建了模式。

我看到的其中一个问题是：

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

我也同意了这个许可。

Answer 1

我失踪了： dependency.OnChange += new OnChangeEventHandler(OnChange); 新代码如下：

               SqlDependency dependency = new SqlDependency(command);

               dependency.OnChange += new OnChangeEventHandler(OnChange);

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

SqlDependency没有触发

1 个答案: