Indicates that a cache entry has no sliding expiration time.
Assembly: System.Runtime.Caching (in System.Runtime.Caching.dll)
Expiration that is based on duration or a defined window of time is also referred to as sliding expiration. Normally, a cache implementation that evicts items that are based on sliding expiration will remove an item that has not been accessed in the specified window of time.
A cache entry that is inserted into the cache with the field value set as the expiration value should never be evicted because of non-activity in a sliding time window. However, a cache item can be evicted if it has an absolute expiration, or if some other eviction event occurs, such a change monitor or memory pressure.
Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.