c# .Net 缓存使用System.Runtime.Caching 做缓存平滑过期，绝对过期-白红宇

c# .Net 缓存使用System.Runtime.Caching 做缓存平滑过期，绝对过期

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发布时间：2019-06-22

本文共 5870 字，大约阅读时间需要 19 分钟。

1 public class CacheHeloer  2 {  3   4     ///   5     /// 默认缓存  6     /// 
  7     private static CacheHeloer Default { get { return new CacheHeloer(); } }  8   9     ///  10     /// 缓存初始化 11     /// 
 12     private MemoryCache cache = MemoryCache.Default; 13  14     ///  15     /// 锁 16     /// 
 17     private object locker = new object(); 18  19     ///  20     /// 构造器 21     /// 
 22     private CacheHeloer() 23     { 24         //CacheItemPolicy policy = new CacheItemPolicy();  //创建缓存项策略 25         ////过期时间设置,以下两种只能设置一种 26         //policy.AbsoluteExpiration = new DateTimeOffset(DateTime.Now.AddMinutes(5)); //设定某个时间过后将逐出缓存 27         //policy.SlidingExpiration = new TimeSpan(0, 0, 10);    //设定某个时间段内未被访问将逐出缓存 28         ////逐出通知,以下两种只能设置一种 29         //policy.UpdateCallback = arguments => { Console.WriteLine("即将逐出缓存" + arguments.Key); }; 30     } 31  32     ///  33     /// 从缓存中获取对象 34     /// 
 35     /// 
     
      对象类型
      36     /// 键 37     /// 
     
      缓存对象
      38     public static object Get(string key) 39     { 40         return Default.GetFromCache(key); 41     } 42  43     ///  44     /// 从缓存中获取对象 45     /// 
 46     /// 
     
      对象类型
      47     /// 键 48     /// 
     
      缓存对象
      49     private object GetFromCache(string key) 50     { 51         lock (locker) 52         { 53             if (cache.Contains(key)) 54             { 55                 return cache[key]; 56             } 57             return null; 58         } 59     } 60  61     ///  62     /// 设置缓存指定时间未访问过期 63     /// 
 64     /// 
     
      对象
      65     /// 键 66     /// 数据对象 67     /// 过期时间 68     public static bool Set(string key, Object value, TimeSpan expiresIn) 69     { 70         var policy = new CacheItemPolicy() 71         { 72             SlidingExpiration = expiresIn 73         }; 74         return Default.SetToCache(key, value, policy); 75     } 76     ///  77     /// 设置缓存绝对时间过期 78     /// 
 79     /// 
      80     ///  81     ///  82     ///  83     /// 
      84     public static bool Set(string key, Object value, DateTimeOffset expiresIn) 85     { 86         var policy = new CacheItemPolicy() 87         { 88             AbsoluteExpiration = expiresIn 89         }; 90         return Default.SetToCache(key, value, policy); 91     } 92  93     ///  94     /// 添加到缓存 95     /// 
 96     /// 
     
      缓存对象类型
      97     /// 键 98     /// 值 99     /// 
     
      结果状态
     100     public static bool Set(string key, object value)101     {102         CacheItemPolicy policy = new CacheItemPolicy()103         {104             Priority = CacheItemPriority.NotRemovable,105         };106         return Default.SetToCache(key, value, policy);107     }108 109     /// 110     /// 数据对象装箱缓存111     /// 
112     /// 
     
      对象
     113     /// 键114     /// 数据对象115     /// 过期时间116     private bool SetToCache(string key, object value, CacheItemPolicy policy)117     {118         lock (locker)119         {120             cache.Set(key, value, policy);121             return true;122         }123     }124 125     /// 126     /// 获取键的集合127     /// 
128     /// 
     
      键的集合
     129     public static ICollection
     
       Keys()130     {131         return Default.GetCacheKeys();132     }133 134     /// 
      135     /// 获取键的集合136     /// 
137     /// 
      
       键的集合
      138     private ICollection
      
        GetCacheKeys()139     {140         lock (locker)141         {142             IEnumerable
       
        
         > items = cache.AsEnumerable();143             return items.Select(m => m.Key).ToList();144         }145     }146 147     /// 
         148     /// 判断缓存中是否有此对象149     /// 
150     /// 
         键151     /// 
         
          是否存在
         152     public static bool Contain(string key)153     {154         return Default.ContainKey(key);155     }156 157     /// 
         158     /// 判断缓存中是否有此对象159     /// 
160     /// 
         键161     /// 
         
          是否存在
         162     private bool ContainKey(string key)163     {164         lock (locker)165         {166             return cache.Contains(key);167         }168     }169 170     /// 
         171     /// 数据对象从缓存对象中移除172     /// 
173     /// 
         键174     public static bool Remove(string key)175     {176         return Default.RemoveFromCache(key);177     }178 179     /// 
         180     /// 数据对象从缓存对象中移除181     /// 
182     /// 
         键183     private bool RemoveFromCache(string key)184     {185         lock (locker)186         {187             if (cache.Contains(key))188             {189                 cache.Remove(key);190                 return true;191             }192             return false;193         }194     }195 196     /// 
         197     /// 清除实例198     /// 
199     public static void Clear()200     {201         Default.ClearCache();202     }203 204     /// 
         205     /// 清除实例206     /// 
207     private void ClearCache()208     {209         lock (locker)210         {211             cache.ToList().ForEach(m => cache.Remove(m.Key));212         }213     }214 215     /// 
         216     /// 获取缓存对象集合217     /// 
218     /// 
         
          缓存对象类型
         219     /// 
         
          缓存对象集合
         220     public static ICollection
         
           Values
          
           ()221 {222 return Default.GetValues
           
            ();223 }224 225 /// 
            226 /// 获取缓存对象集合227 /// 
228 /// 
            
             缓存对象类型
            229 /// 
            
             缓存对象集合
            230 private ICollection
            
              GetValues
             
              ()231 {232 lock (locker)233 {234 IEnumerable
              
               
                > items = cache.AsEnumerable();235 return items.Select(m => (T)m.Value).ToList();236 }237 }238 239 /// 
                240 /// 获取缓存尺寸241 /// 
242 /// 
                
                 缓存尺寸
                243 public static long Size()244 {245 return Default.GetCacheSize();246 }247 248 /// 
                249 /// 获取缓存尺寸250 /// 
251 /// 
                
                 缓存尺寸
                252 private long GetCacheSize()253 {254 lock (locker)255 {256 return cache.GetCount();257 }258 }259 }