HttpCache缓存扩展方法

using System;
using System.Collections;
using System.Configuration;
using System.Web;
using System.Web.Caching;

namespace Meb.Common.Extensions
{
//缓存写入
//验证缓存是否存在
//缓存读取 按缓存索引读取相应缓存值
public static class CacheExtension
{
//private static int CacheMinute = int.Parse(ConfigurationManager.AppSettings["CacheMinute"] ?? "30");

/// <summary>
/// 获取当前应用程序指定CacheKey的Cache值
/// </summary>
/// <param name="cacheKey"></param>
/// <returns></returns>
public static object GetCache(string cacheKey)
{
var objCache = HttpRuntime.Cache;
return objCache[cacheKey];
}
/// <summary>
/// 查询指定CacheKey的Cache值是否存在
/// </summary>
/// <param name="cacheKey"></param>
/// <returns></returns>
public static bool IsExistsCache(string cacheKey)
{
var objCache = HttpRuntime.Cache;
return objCache[cacheKey] != null;
}

/// <summary>
/// 设置当前应用程序指定CacheKey的Cache值
/// </summary>
/// <param name="cacheKey"></param>
/// <param name="objObject"></param>
public static void SetCache(string cacheKey, object objObject)
{
var objCache = HttpRuntime.Cache;
objCache.Insert(cacheKey, objObject);
}

/// <summary>
/// 设置当前应用程序指定CacheKey的Cache值
/// </summary>
/// <param name="cacheKey"></param>
/// <param name="objObject"></param>
/// <param name="absoluteExpiration"></param>
/// <param name="slidingExpiration"></param>
public static void SetCache(string cacheKey, object objObject, DateTime absoluteExpiration, TimeSpan slidingExpiration)
{
var objCache = HttpRuntime.Cache;
objCache.Insert(cacheKey, objObject, null, absoluteExpiration, slidingExpiration);
}
/// <summary>
/// 设置数据缓存
/// </summary>
public static void SetCache(string cacheKey, object objObject, TimeSpan timeout)
{
var objCache = HttpRuntime.Cache;
objCache.Insert(cacheKey, objObject, null, DateTime.MaxValue, timeout, CacheItemPriority.NotRemovable, null);
}
/// <summary>
/// 移除指定数据缓存
/// </summary>
public static void RemoveAllCache(string cacheKey)
{
var cache = HttpRuntime.Cache;
cache.Remove(cacheKey);
}
/// <summary>
/// 移除全部缓存
/// </summary>
public static void RemoveAllCache()
{
var cache = HttpRuntime.Cache;
var cacheEnum = cache.GetEnumerator();
while (cacheEnum.MoveNext())
{
cache.Remove(cacheEnum.Key.ToString());
}
}

private static int CacheMinute = int.Parse(ConfigurationManager.AppSettings["CacheMinute"] ?? "30");
private const string ApplicationCacheKeyFormat = "Application_{0}";
private const string UserInfoCacheKeyFormat = "UserInfo_{0}";
private const string RolePopedomCacheKeyFormat = "RolePopedom_{0}";

public static void InsertForSlidingExpiration(this Cache cache, string key, object value)
{
cache.Insert(key, value, null, Cache.NoAbsoluteExpiration, TimeSpan.FromMinutes(CacheMinute));
}

public static T Get<T>(this Cache cache, object dataCacheKey, Func<object[], T> getService) where T : class
{
var cacheKey = string.Format("{0}_{1}", typeof(T).FullName, dataCacheKey);
var data = cache.Get(cacheKey) as T;
if (data != null)
{
return data;
}
data = getService(new object[] { dataCacheKey });
if (data != null)
{
cache.InsertForSlidingExpiration(cacheKey, data);
return data;
}
return null;
}

public static void Remove<T>(this Cache cache, object dataCacheKey)
{
var cacheKey = string.Format("{0}_{1}", typeof(T).FullName, dataCacheKey);
cache.Remove(cacheKey);
}
}
}