使用Hashtable没有任何优点，因为在.net2.0以后已经被Dictionary<Tkey,TValue>所代替。

他们两者的区别是，根据*

Dictionary relies on chaining (maintaining a list of items for each hash table bucket) to resolve collisions whereas Hashtable
uses rehashing for collision resolution (when a collision occurs, tries another hash function to map the key to a bucket)