如何获取HttpRuntime.Cache对象的“缓存项优先级”？

Question

是否可以获得HttpRuntime.Cache对象的Cache项优先级？

如果是这样，最好的方法是什么？

Answer 1

您可以使用此：

public static DateTime GetCachePriority(string strKey)
{
    object cacheProvider = HttpRuntime.Cache.GetType().GetProperty("InternalCache", BindingFlags.Instance | BindingFlags.NonPublic)?.GetValue(HttpRuntime.Cache, null);
                object intenralCacheStore = cacheProvider?.GetType().GetField("_cacheInternal", BindingFlags.Instance | BindingFlags.NonPublic)?.GetValue(cacheProvider);
                if(intenralCacheStore != null)
                {
                    Type cacheOption = HttpRuntime.Cache.GetType().Assembly.GetTypes().FirstOrDefault(d => d.Name == "CacheGetOptions");
                    MethodInfo methodInfo = intenralCacheStore.GetType().GetMethod("DoGet", BindingFlags.NonPublic | BindingFlags.Instance, null, CallingConventions.Any,
                                                                                   new[] { typeof(bool), typeof(string), cacheOption }, null);

                    if(methodInfo != null)
                    {
                        dynamic cacheEntry = methodInfo.Invoke(intenralCacheStore, new Object[] { true, strKey, 1 });

                        PropertyInfo usageBucketProperty = cacheEntry.GetType().GetProperty("UsageBucket", BindingFlags.NonPublic | BindingFlags.Instance);
                        byte byPriority = (byte) usageBucketProperty.GetValue(cacheEntry, null);
                        CacheItemPriority prriority = byPriority == byte.MaxValue ? CacheItemPriority.NotRemovable : (CacheItemPriority)byPriority + 1;
                        strPriority = prriority.ToString();
                    }
                }
}

谢谢。