DataCacheNotificationCallback Delegate
Represents a callback method that is to be invoked by a cache notification when one or more cache operations take place. Applies only to the server versions of AppFabric.
Namespace: Microsoft.ApplicationServer.Caching
Assembly: Microsoft.ApplicationServer.Caching.Client (in Microsoft.ApplicationServer.Caching.Client.dll)
'Declaration Public Delegate Sub DataCacheNotificationCallback ( _ cacheName As String, _ regionName As String, _ key As String, _ version As DataCacheItemVersion, _ cacheOperation As DataCacheOperations, _ nd As DataCacheNotificationDescriptor _ ) 'Usage Dim instance As New DataCacheNotificationCallback(AddressOf HandlerMethod)
Parameters
- cacheName
- Type: System..::..String
- regionName
- Type: System..::..String
The name of the region associated with the cache operation. A zero-length string indicates that a specific region is not associated with the cache operation.
- key
- Type: System..::..String
The name of the key associated with the cache operation. A zero-length string indicates that a specific cached item is not associated with the cache operation.
- version
- Type: Microsoft.ApplicationServer.Caching..::..DataCacheItemVersion
The DataCacheItemVersion of the cached object associated with the cache operation that triggered the notification. A null version indicates that a specific cached item is not associated with the cache operation.
- cacheOperation
- Type: Microsoft.ApplicationServer.Caching..::..DataCacheOperations
The DataCacheOperations enumeration specifying which cache event triggered the cache notification.
- nd
- Type: Microsoft.ApplicationServer.Caching..::..DataCacheNotificationDescriptor
The DataCacheNotificationDescriptor object associated with the cache notification that invoked the delegate method.
Adding a cache notification callback requires two steps. First, create a method that should be invoked when a cache notification is triggered by one or more cache operations. The method you invoke with the cache notifications must accept the same parameters as the DataCacheNotificationCallback delegate. Second, add a callback using one of the three available methods from the DataCache object: AddCacheLevelCallback(DataCacheOperation, DataCacheNotificationCallback), AddRegionLevelCallback(String, DataCacheOperation, DataCacheNotificationCallback), or [Override:Microsoft.ApplicationServer.Caching.DataCache.AddItemLevelCallback].
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In order for your application to use notifications, you need to enable them on a named cache. In Microsoft AppFabric 1.1 for Windows Server Caching, use the notificationsEnabled parameter with the New-Cache or Set-CacheConfig Windows PowerShell commands. In Windows Azure Caching, enable notifications in the Caching configuration of the role that hosts the cache. |
The DataCacheNotificationDescriptor object passed to the delegate method with the nd parameter can be used to unsubscribe from the cache notification. For more information, see .
Note