MemoryCache.Default remove using LINQ

Question

Is there a way i can remove objects from MemoryCache.Default using LINQ query like this:

MemoryCache.Default.Select(c => c.Value).OfType<CachedObjectType>().ToList().RemoveAll(k => k.ZipCode == "11111");

This doesnt remove the objects from the MemoryCache.Default instance.

Answer 1

Since you are projecting you are working with a new list, not the original one, LINQ is not the right tool for mutation - also you need the key of the item to remove, not the value.

This should work:

var itemsToRemove = MemoryCache.Default
                               .Where( x=> x.Value is CachedObjectType &&
                                          (x.Value as CachedObjectType).ZipCode == "11111")
                               .Select(x=> x.Key)
foreach(var key in itemsToRemove)
    MemoryCache.Default.Remove(key);