MemoryCache的使用

 using System.Runtime.Caching;

MemoryCache mc = MemoryCache.Default;
  string cacheKey = "mykey";
　　var value = "";
  if (mc.Contains(cacheKey))
  {
       var cacheItem = mc.Get(cacheKey);
       value = cacheItem as string;
  }
 else
   {
  　value = "5555";
 　　CacheItemPolicy policy = new CacheItemPolicy();
     policy.AbsoluteExpiration = DateTime.Now.AddMinutes(100);
     mc.Add(cacheKey, value , policy);
 
}