Mar
27
2009
Adding Items to the Cache, Retrieving the Items, and Clearing the Cache
When working with a web application that contains data items that do not change too often, it improves the performance of the application to store data items in the server cache and retrieve those items from the cache instead of making an extra trip to the database. Also clearing the cache when a item does change is important for your application.
'*** The cache key is used to uniquely identify the cache items
Dim CacheKey As String = "SomeKey"
'*** Get the the amount of time the object stays in the cache from web config
Dim CacheTime As Double = CDbl(ConfigurationManager.AppSettings("cachetime"))
If Cache(CacheKey) Is Nothing Then
'*** Create the objItem
Dim objItem as Item
'*** Add the object to the cache
Cache.Add(CacheKey, objItem, Nothing, Now().AddMinutes(CacheTime), Nothing, _
CacheItemPriority.Normal, Nothing)
Else
'*** Pull the data from the cache
Dim objItem As Item = Cache(CacheKey)
End If
Clearing all the cache of an ASP.Net application:
For Each de As DictionaryEntry In HttpContext.Current.Cache
HttpContext.Current.Cache.Remove(DirectCast(de.Key, String))
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