MemoryCache.CreateCacheEntryChangeMonitor Method (IEnumerable<String>, String)

.NET Framework (current version)

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Creates a CacheEntryChangeMonitor object that can trigger events in response to changes to specified cache entries.

Namespace:   System.Runtime.Caching
Assembly:  System.Runtime.Caching (in System.Runtime.Caching.dll)

public override CacheEntryChangeMonitor CreateCacheEntryChangeMonitor(
	IEnumerable<string> keys,
	string regionName = null


Type: System.Collections.Generic.IEnumerable<String>

An enumeration of unique cache entry keys for the CacheEntryChangeMonitor object.

Type: System.String

A named region in the cache to which a cache entry can be added. Do not pass a value for this parameter. This parameter is null by default, because the MemoryCache class does not implement regions.

Return Value

Type: System.Runtime.Caching.CacheEntryChangeMonitor

A change monitor that monitors entries in the cache.

Exception Condition

regionName is not null.


keys is null.


The number of items in keys is zero.


An item in the keys collection is null.

The CreateCacheEntryChangeMonitor method creates a CacheEntryChangeMonitor instance. This specialized change monitor is used to monitor the cache entries that are specified in the keys collection and to trigger events when the entries change.

A monitored entry is considered to have changed for any of the following reasons:

  • The key does not exist at the time of the call to the CreateCacheEntryChangeMonitor method. In that case, the resulting CacheEntryChangeMonitor instance is immediately set to a changed state. This means that when code subsequently binds a change-notification callback, the callback is triggered immediately.

  • The associated cache entry was removed from the cache. This can occur if the entry is explicitly removed, if it expires, or if it is evicted to recover memory

.NET Framework
Available since 4.0
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