DataCache.AddItemLevelCallback Method (String, DataCacheOperations, DataCacheNotificationCallback)


Adds a cache notification callback for cache operations occurring on one specific item that is not stored in a region. Not supported in Windows Azure Shared Caching.

Namespace:   Microsoft.ApplicationServer.Caching
Assembly:  Microsoft.ApplicationServer.Caching.Client (in Microsoft.ApplicationServer.Caching.Client.dll)

public DataCacheNotificationDescriptor AddItemLevelCallback(
	string key,
	DataCacheOperations filter,
	DataCacheNotificationCallback clientCallback


Type: System.String

The key used to store the object in the cache.

Type: Microsoft.ApplicationServer.Caching.DataCacheOperations

The type of cache operation(s) that will trigger cache notifications.

Type: Microsoft.ApplicationServer.Caching.DataCacheNotificationCallback

The name of the method you want to invoke when these notifications occur.

Return Value

Type: Microsoft.ApplicationServer.Caching.DataCacheNotificationDescriptor

A DataCacheNotificationDescriptor object used to identify the cache notification callback.

Only item operations AddItem, ReplaceItem, and RemoveItem can trigger cache notifications with item-level callbacks. Specifying region operations in the filter parameter will cause an exception.

Use the DataCacheOperations enumeration in the filter parameter to specify what type of item operations you want to trigger cache notifications. Select more than one enumeration by separating the enumerations with the binary OR operator to perform a bitwise OR. To do this, use the | character in C#, and the Or operator in Visual Basic.

The clientCallback method you invoke with the cache notification must accept the same parameters as the DataCacheNotificationCallback delegate.


In order for your application to use notifications, you need to enable them on a named cache. For Windows Server AppFabric Caching, use the NotificationsEnabled parameter with the New-Cache or Set-CacheConfig Windows PowerShell commands. For Windows Azure Caching on roles, enable notifications in the cache settings.

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