好用的Cache輔助工具類

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections;
using System.Web;
using System.Web.Caching;

namespace Tools
{
    /// <summary>
    /// 緩存輔助類
    /// </summary>
    public static class CacheHelper
    {
        /// <summary>
        /// 緩存
        /// </summary>
        private static Cache cache = HttpRuntime.Cache;

        /// <summary>
        /// 根據鍵獲取緩存數據
        /// </summary>
        /// <param name="cacheKey">緩存的鍵</param>
        /// <returns></returns>
        private static object GetCache(string cacheKey)
        {
            return cache.Get(cacheKey);
        }

        /// <summary>
        ///  設置緩存
        /// </summary>
        /// <param name="cacheKey">緩存的鍵</param>
        /// <param name="objValue">緩存的值</param>
        private static void SetCache(string cacheKey, object objValue)
        {
            cache.Insert(cacheKey, objValue);
        }

        /// <summary>
        /// 設置緩存
        /// </summary>
        /// <param name="cacheKey">緩存的鍵</param>
        /// <param name="objValue">緩存的值</param>
        /// <param name="slidingExpiration">滑動過期時間</param>
        private static void SetCache(string cacheKey, object objValue, TimeSpan slidingExpiration)
        {
            cache.Insert(cacheKey, objValue, null, Cache.NoAbsoluteExpiration, slidingExpiration);
        }

        /// <summary>
        /// 設置緩存
        /// </summary>
        /// <param name="cacheKey">緩存的鍵</param>
        /// <param name="objValue">緩存的值</param>
        /// <param name="absoluteExpiration">絕對過期時間</param>
        /// <param name="slidingExpiration">滑動過期時間</param>
        private static void SetCache(string cacheKey, object objValue, DateTime absoluteExpiration)
        {
            cache.Insert(cacheKey, objValue, null, absoluteExpiration, Cache.NoSlidingExpiration);
        }

        /// <summary>
        /// 移除指定的緩存
        /// </summary>
        /// <param name="cacheKey">緩存的鍵</param>
        public static void Remove(string cacheKey)
        {
            cache.Remove(cacheKey);
        }

        /// <summary>
        /// 移除全部緩存
        /// </summary>
        public static void Remove()
        {
            IDictionaryEnumerator CacheEnum = cache.GetEnumerator();
            while (CacheEnum.MoveNext())
            {
                cache.Remove(CacheEnum.Key.ToString());
            }
        }

        /// <summary>
        /// 從緩存中獲取數據。緩存中不存在的時候，從回調方法getDate中獲取，並設置進緩存。
        /// </summary>
        /// <typeparam name="T">緩存的數據類型</typeparam>
        /// <param name="cacheKey">緩存的鍵</param>
        /// <param name="getData">回調方法</param>
        /// <returns>緩存中的數據</returns>
        public static T Get<T>(string cacheKey, Func<T> getData)
        {
            var data = GetCache(cacheKey);
            if (data == null)
            {
                data = getData();
                SetCache(cacheKey, data);
            }
            return (T)data;
        }
        
        /// <summary>
        /// 從緩存中獲取數據。緩存中不存在的時候，從回調方法getDate中獲取，並設置進緩存。
        /// </summary>
        /// <typeparam name="T">緩存的數據類型</typeparam>
        /// <param name="cacheKey">緩存的鍵</param>
        /// <param name="slidingExpiration">滑動過期時間</param>
        /// <param name="getData">回調方法</param>
        /// <returns>緩存中的數據</returns>
        public static T Get<T>(string cacheKey, TimeSpan slidingExpiration, Func<T> getData)
        {
            var data = GetCache(cacheKey);
            if (data == null)
            {
                data = getData();
                SetCache(cacheKey, data, slidingExpiration);
            }
            return (T)data;
        }

        /// <summary>
        /// 從緩存中獲取數據。緩存中不存在的時候，從回調方法getDate中獲取，並設置進緩存。
        /// </summary>
        /// <typeparam name="T">緩存的數據類型</typeparam>
        /// <param name="cacheKey">緩存的鍵</param>
        /// <param name="absoluteExpiration">絕對過期時間</param>
        /// <param name="getData">回調方法</param>
        /// <returns>緩存中的數據</returns>
        public static T Get<T>(string cacheKey, DateTime absoluteExpiration, Func<T> getData)
        {
            var data = GetCache(cacheKey);
            if (data == null)
            {
                data = getData();
                SetCache(cacheKey, data, absoluteExpiration);
            }
            return (T)data;
        }
    }
}