为什么不'；t SQL Server Service Broker通知我插入表

我已经建立了一个列表，应该知道它的数据源的更改，或多或少如下：

public class SharedList<T>: ObservableCollection<T> where T: XTimeEntity
{
    private const string DependencyQuery = "select TITLE_ACTIVE, TITLE_NAME from TITLE";
    private readonly SqlDependency _dependency = new SqlDependency();
    public SharedList()
    {
        var connectionString = ConfigurationManager.ConnectionStrings["XTime900Context"].ConnectionString;
        SqlDependency.Stop(connectionString);
        using (var sqn = new SqlConnection(connectionString))
        {
            using (var cmd = new SqlCommand(DependencyQuery, sqn))
            {
                _dependency.AddCommandDependency(cmd);
            }
        }
        _dependency.OnChange += DependencyOnOnChange;
        PopulateList();
        SqlDependency.Start(connectionString);
    }
}

然而，当我在SSMS中执行insert TITLE values (1, 1, 'Mr.')时，没有触发任何事件。触发事件的更改是否必须对SqlConnection对象或其他对象进行？