DataCache.AddItemLevelCallback Method (String, DataCacheOperations, DataCacheNotificationCallback)

Article
08/26/2011

Adds a cache notification callback for cache operations occurring on one specific item that is not stored in a region.

Namespace: Microsoft.ApplicationServer.Caching
Assembly: Microsoft.ApplicationServer.Caching.Client (in microsoft.applicationserver.caching.client.dll)

Usage

'Usage
Dim instance As DataCache
Dim key As String
Dim filter As DataCacheOperations
Dim clientCallback As DataCacheNotificationCallback
Dim returnValue As DataCacheNotificationDescriptor

returnValue = instance.AddItemLevelCallback(key, filter, clientCallback)

Syntax

'Declaration
Public MustOverride Function AddItemLevelCallback ( _
    key As String, _
    filter As DataCacheOperations, _
    clientCallback As DataCacheNotificationCallback _
) As DataCacheNotificationDescriptor

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

public:
virtual DataCacheNotificationDescriptor^ AddItemLevelCallback (
    String^ key, 
    DataCacheOperations filter, 
    DataCacheNotificationCallback^ clientCallback
) abstract

public abstract DataCacheNotificationDescriptor AddItemLevelCallback (
    String key, 
    DataCacheOperations filter, 
    DataCacheNotificationCallback clientCallback
)

public abstract function AddItemLevelCallback (
    key : String, 
    filter : DataCacheOperations, 
    clientCallback : DataCacheNotificationCallback
) : DataCacheNotificationDescriptor

Parameters

key
The key used to store the object in the cache.

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

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

Return Value

A DataCacheNotificationDescriptor object used to identify the cache notification callback.

Remarks

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.

For more information about using this method, see How to: Add a Cache Notification Callback. For more information about cache notifications, see Cache Notifications.

Note

In order for your application to use notifications, you need to enable them on a named cache. Use the NotificationsEnabled parameter with the New-Cache or Set-CacheConfig commands. For more information, see Cache Administration with PowerShell.

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Platforms

Development Platforms

Visual Studio 2010 and later, .NET Framework 4

Target Platforms

Windows 7; Windows Server 2008 R2; Windows Server 2008 Service Pack 2; Windows Vista Service Pack 2