public CacheItem Get(string key)
{
CacheItem item = null;
ReadOnlyCollection <string> keys = _CacheKeysReadOnly;
if (!keys.Contains(key))
{
lock (_SynchObj)
{
keys = _CacheKeysReadOnly;
if (!keys.Contains(key))
{
item = new CacheItem();
item.ExpensiveLoad();
_Cache.Add(key, item);
List <string> newKeys = new List <string>(_CacheKeysReadOnly);
newKeys.Add(key);
_CacheKeysReadOnly = newKeys.AsReadOnly();
}
}
}
return(item);
}