MemoryCache::AddOrGetExisting Method (String^, Object^, DateTimeOffset, String^)
Adds a cache entry into the cache using the specified key and a value and an absolute expiration value.
Assembly: System.Runtime.Caching (in System.Runtime.Caching.dll)
public: virtual Object^ AddOrGetExisting( String^ key, Object^ value, DateTimeOffset absoluteExpiration, String^ regionName = null ) override
Parameters
- key
-
Type:
System::String^
A unique identifier for the cache entry to add.
- value
-
Type:
System::Object^
The data for the cache entry.
- absoluteExpiration
-
Type:
System::DateTimeOffset
The fixed date and time at which the cache entry will expire.
- regionName
-
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::Object^If a cache entry with the same key exists, the existing cache entry; otherwise, null.
| Exception | Condition | ||
|---|---|---|---|
| ArgumentNullException | key is null. | ||
| NotSupportedException | regionName is not null. | ||
| ArgumentNullException | value is not null. | ||
| ArgumentException | An UpdateCallback property has been supplied.
| ||
| ArgumentException | Both the absolute and sliding expiration values for the CacheItemPolicy object are set to values other than the defaults of InfiniteAbsoluteExpiration and NoSlidingExpiration fields. The MemoryCache class cannot set expiration policy based on a combination of an absolute expiration and a sliding expiration. Only one expiration setting can be explicitly set when you use the MemoryCache instance. The other expiration setting must be set to InfiniteAbsoluteExpiration or NoSlidingExpiration | ||
| ArgumentOutOfRangeException | The SlidingExpiration property is set to a value less than Zero. -or- The SlidingExpiration property is set to a value greater than one year. -or- The Priority property is not a value of the CacheItemPriority enumeration. |
If the cache does not have a cache entry whose key matches the key parameter, a new cache entry is created, and the MemoryCache::AddOrGetExisting method overload returns null. If a matching cache entry exists, the existing entry is returned.
Warning |
|---|
The Add and AddOrGetExisting method overloads do not support the UpdateCallback property. Therefore, to set the UpdateCallback property for a cache entry, use the Set method overloads instead. |
Available since 4.0

