/// <summary>
/// 檢查快取位址是否有值，無則使用create查詢2
/// </summary>
/// <typeparam name="TValue"></typeparam>
/// <param name="cache"></param>
/// <param name="key"></param>
/// <param name="create"></param>
/// <param name="absoluteExpiration"></param>
/// <param name="slidingExpiration"></param>
/// <returns></returns>
public static TValue GetOrStore <TValue>(this System.Runtime.Caching.ObjectCache cache,
string key,
Func <string, TValue> create,
DateTimeOffset absoluteExpiration, TimeSpan slidingExpiration)
{
var instance = cache.GetOrStoreContainer <TValue>(key, absoluteExpiration, slidingExpiration);
if (instance.Value == null)
{
lock (instance)
if (instance.Value == null)
{
instance.Value = create(key);
}
}
return(instance.Value);
}