How to: Add a Cache Notification Callback (Velocity)

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, AddRegionLevelCallback, or AddItemLevelCallback. Use the filter parameter to define the types of cache operations you want to trigger cache notifications. Use the name of the method you created in the first step for the clientDelegate parameter.

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 (Velocity).

How to add a callback for one or more cache operations
Create the method you want to be triggered by the cache notification. Make sure the method accepts the same parameters as the DataCacheNotificationCallback delegate.

Add a callback. Use one of the three available methods from the DataCache object to define the notification scope: AddCacheLevelCallback, AddRegionLevelCallback, or AddItemLevelCallback.

Use the DataCacheOperation enumeration in the filter parameter to specify what type of cache operations you want to trigger 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.

Use the name of the method you want to invoke when these notifications occur in the clientDelegate parameter.

Set the add callback method equal to a DataCacheNotificationDescriptor object that you can use elsewhere in your program to remove the cache notification callback.