Gets or sets a user-defined key dependency that is linked to all data cache objects created by the data source control. All cache objects explicitly expire when the key expires.
Assembly: System.Web (in System.Web.dll)
The XmlDataSource control supports data caching. While data is cached, the XmlDataSource retrieves data from the cache rather than from the underlying data file. When the cache expires, it retrieves data from the underlying file and re-caches the data.
You can set the property to create a dependency between all cache entries created by the XmlDataSource control and the key. You can programmatically invalidate all the cache entries at any time by expiring the key.
Because of the properties used to create the , it is possible that multiple XmlDataSource controls can use the same cache in scenarios where they load the same data from the same XML file and transform file and have the same CacheDuration and CacheExpirationPolicy set.