The exception that is thrown when a SqlCacheDependency class is used against a database table that is not enabled for change notifications.
Assembly: System.Web (in System.Web.dll)
Thetype exposes the following members.
|TableNotEnabledForNotificationException||Initializes a new instance of the class.|
|TableNotEnabledForNotificationException(String)||Initializes a new instance of the class with the specified error message.|
|TableNotEnabledForNotificationException(String, Exception)||Initializes a new instance of the class with a specified error message and a reference to the inner exception that is the cause of this exception.|
|Data||Gets a collection of key/value pairs that provide additional user-defined information about the exception. (Inherited from Exception.)|
|HelpLink||Gets or sets a link to the help file associated with this exception. (Inherited from Exception.)|
|HResult||Gets or sets HRESULT, a coded numerical value that is assigned to a specific exception. (Inherited from Exception.)|
|InnerException||Gets the Exception instance that caused the current exception. (Inherited from Exception.)|
|Message||Gets a message that describes the current exception. (Inherited from Exception.)|
|Source||Gets or sets the name of the application or the object that causes the error. (Inherited from Exception.)|
|StackTrace||Gets a string representation of the immediate frames on the call stack. (Inherited from Exception.)|
|TargetSite||Gets the method that throws the current exception. (Inherited from Exception.)|
|Equals(Object)||Determines whether the specified object is equal to the current object. (Inherited from Object.)|
|GetBaseException||When overridden in a derived class, returns the Exception that is the root cause of one or more subsequent exceptions. (Inherited from Exception.)|
|GetHashCode||Serves as the default hash function. (Inherited from Object.)|
|GetObjectData||When overridden in a derived class, sets the SerializationInfo with information about the exception. (Inherited from Exception.)|
|GetType||Gets the runtime type of the current instance. (Inherited from Exception.)|
|ToString||Creates and returns a string representation of the current exception. (Inherited from Exception.)|
The following code example attempts to create a SqlCacheDependency object and add an item to the Cache with a dependency on the SqlCacheDependency object. If the SQL Server database table is not enabled for dependency notifications, the is thrown and handled by calling the SqlCacheDependencyAdmin.EnableTableForNotifications method.
Sub Page_Load(Src As Object, E As EventArgs) ' Declare the SqlCacheDependency instance, SqlDep. Dim SqlDep As SqlCacheDependency ' Check the Cache for the SqlSource key. ' If it isn't there, create it with a dependency ' on a SQL Server table using the SqlCacheDependency class. If Cache("SqlSource") Is Nothing ' Because of possible exceptions thrown when this ' code runs, use Try...Catch...Finally syntax. Try ' Instantiate SqlDep using the SqlCacheDependency constructor. SqlDep = New SqlCacheDependency("Northwind", "Categories") ' Handle the DatabaseNotEnabledForNotificationException with ' a call to the SqlCacheDependencyAdmin.EnableNotifications method. Catch exDBDis As DatabaseNotEnabledForNotificationException Try SqlCacheDependencyAdmin.EnableNotifications("Northwind") ' If the database does not have permissions set for creating tables, ' the UnauthorizedAccessException is thrown. Handle it by redirecting ' to an error page. Catch exPerm As UnauthorizedAccessException Response.Redirect(".\ErrorPage.htm") End Try ' Handle the TableNotEnabledForNotificationException with ' a call to the SqlCacheDependencyAdmin.EnableTableForNotifications method. Catch exTabDis As TableNotEnabledForNotificationException Try SqlCacheDependencyAdmin.EnableTableForNotifications( _ "Northwind", "Categories") ' If a SqlException is thrown, redirect to an error page. Catch exc As SqlException Response.Redirect(".\ErrorPage.htm") End Try ' If all the other code is successful, add MySource to the Cache ' with a dependency on SqlDep. If the Categories table changes, ' MySource will be removed from the Cache. Then generate a message ' that the data is newly created and added to the cache. Finally Cache.Insert("SqlSource", Source1, SqlDep) CacheMsg.Text = "The data object was created explicitly." End Try Else CacheMsg.Text = "The data was retrieved from the Cache." End If End Sub