时髦的Contains()方法的写法

   1: public bool Exists(Predicate<VALUE> predicate)

   2:         {

   3:             bool returnValue = false;

   4:  

   5:             Each(delegate(VALUE value) { returnValue |= predicate(value); });

   6:  

   7:             return returnValue;

   8:         }

   9:  

  10: public void Each(Action<VALUE> action)

  11:         {

  12:             foreach (var pair in _values)

  13:             {

  14:                 action(pair.Value);

  15:             }

  16:         }

  17:  

  18: private readonly IDictionary<KEY, VALUE> _values;