TableNotEnabledForNotificationException Class
Definition
The exception that is thrown when a SqlCacheDependency class is used against a database table that is not enabled for change notifications.
public ref class TableNotEnabledForNotificationException sealed : SystemException
[System.Serializable]
public sealed class TableNotEnabledForNotificationException : SystemException
[<System.Serializable>]
type TableNotEnabledForNotificationException = class
inherit SystemException
Public NotInheritable Class TableNotEnabledForNotificationException
Inherits SystemException
- Inheritance
- Attributes
Examples
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 TableNotEnabledForNotificationException is thrown and handled by calling the SqlCacheDependencyAdmin.EnableTableForNotifications method.
public void Page_Load(object Src, EventArgs E)
{
// Declare the SqlCacheDependency instance, SqlDep.
SqlCacheDependency SqlDep = null;
// 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"] == null) {
// 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 (DatabaseNotEnabledForNotificationException exDBDis) {
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 (UnauthorizedAccessException exPerm) {
Response.Redirect(".\\ErrorPage.htm");
}
}
// Handle the TableNotEnabledForNotificationException with
// a call to the SqlCacheDependencyAdmin.EnableTableForNotifications method.
catch (TableNotEnabledForNotificationException exTabDis) {
try {
SqlCacheDependencyAdmin.EnableTableForNotifications("Northwind", "Categories");
}
// If a SqlException is thrown, redirect to an error page.
catch (SqlException exc) {
Response.Redirect(".\\ErrorPage.htm");
}
}
// 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.";
}
}
else {
CacheMsg.Text = "The data was retrieved from the Cache.";
}
}
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
Constructors
TableNotEnabledForNotificationException() |
Initializes a new instance of the TableNotEnabledForNotificationException class. |
TableNotEnabledForNotificationException(String) |
Initializes a new instance of the TableNotEnabledForNotificationException class with the specified error message. |
TableNotEnabledForNotificationException(String, Exception) |
Initializes a new instance of the TableNotEnabledForNotificationException class with a specified error message and a reference to the inner exception that is the cause of this exception. |
Properties
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) |
Methods
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(SerializationInfo, StreamingContext) |
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) |
MemberwiseClone() |
Creates a shallow copy of the current Object. (Inherited from Object) |
ToString() |
Creates and returns a string representation of the current exception. (Inherited from Exception) |
Events
SerializeObjectState |
Occurs when an exception is serialized to create an exception state object that contains serialized data about the exception. (Inherited from Exception) |