using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Web;
namespace Cache
{
public class IListCache<T>
{
public delegate IList<T> UpdateDelegate();//该委托不支持传入参数，如需传参请封装一个类
public UpdateDelegate delegate1;//该委托变量用于注册更新缓存的函数指针
static Dictionary<string, IList<T>> DicObj = new Dictionary<string, IList<T>>();//缓存对象
static Dictionary<string, DateTime> DicTime = new Dictionary<string, DateTime>();//超时时间
string CacheKey;//缓存Key
///<summary>
///获取指定CacheKey的缓存
///</summary>
///<param name="ud"></param>
///<param name="CacheKey">缓存KEY</param>
///<returns></returns>
public IList<T> GetCache(string CacheKey)
{
this.CacheKey = CacheKey;
bool isTimeOut = false;
IList<T> obj = GetCache(ref isTimeOut);
if (obj != null)
{
if (isTimeOut) AsyncUpdateCache();
return obj;
}
else
{
return GetObjectAndSetCache();
}
}
///<summary>
///异步更新缓存
///</summary>
void AsyncUpdateCache()
{
Func<IList<T>> albumFunC =new Func<IList<T>>(GetObjectAndSetCache);
albumFunC.BeginInvoke(null,null);
}
IList<T> GetObjectAndSetCache()
{
IList<T> ilt = null;
if (delegate1 != null)
{ //如果有方法注册委托变量
ilt = delegate1(); //通过委托调用方法
}
//通过名称获取对应的缓存时间
int intCache = 60;
int? enumVal =GetExpiredTimeByCacheName(CacheKey);//该缓存时间可从配置文件读取
if (enumVal.HasValue)
{ intCache = enumVal.Value; }
SetCache(ilt, intCache);
return ilt;
}
///<summary>
///获取缓存
///</summary>
///<returns></returns>
IList<T> GetCache(refbool isTimeOut)
{
if (DicObj.ContainsKey(CacheKey))
{
if (DicTime.ContainsKey(CacheKey))
{
isTimeOut = (DateTime.Now > DicTime[CacheKey]);
}
return DicObj[CacheKey];
}
return null;
}
///<summary>
///设置当前应用程序指定CacheKey的Cache对象
///</summary>
///<param name="objObject">Cache值</param>
///<param name="absoluteExpiration">绝对期限</param>
void SetCache(IList<T> objObject,DateTime absoluteExpiration)
{
DicObj[CacheKey] = objObject;
DicTime[CacheKey] = absoluteExpiration;
}
///<summary>
///设置当前应用程序指定CacheKey的Cache对象
///</summary>
///<param name="objObject"></param>
///<param name="expirationMinutes">过期分钟数</param>
void SetCache(IList<T> objObject,int expirationMinutes)
{
DateTime absoluteExpiration =DateTime.Now.AddMinutes(expirationMinutes);
SetCache(objObject, absoluteExpiration);
}
}
}
/// <summary>
/// 读取配置文件的缓存时间设置
/// </summary>
/// <param name="cacheKey"></param>
/// <returns></returns>
private int? GetExpiredTimeByCacheName(string cacheKey)
{
try
{
string s = ConfigurationManager.AppSettings[cacheKey].ToString();
int ret = PublicFun.ToInt(s);
if (ret > 0)
{
return ret;
}
}
catch
{
}
return null;
}