1 ：
Hashtable 支持多个线程读， 同时只有一个线程写 ， dictionary 不支持
Hashtable supports multiple reader threads with a single writer
thread, while Dictionary offers no thread safety. If you need
thread safety with a generic dictionary, you must implement your own
synchronization or (in .NET 4.0) use ConcurrentDictionary<TKey,
TValue>
2 ： hash table 只能用 key 引用， 而不能 foreach , dictionary 可以。
引用 hash table:
public void MethodHashTable() { Hashtable objHashTable = new Hashtable(); objHashTable.Add(1, 100); // int objHashTable.Add(2.99, 200); // float objHashTable.Add(‘A‘, 300); // char objHashTable.Add("4", 400); // string lblDisplay1.Text = objHashTable[1].ToString(); lblDisplay2.Text = objHashTable[2.99].ToString(); lblDisplay3.Text = objHashTable[‘A‘].ToString(); lblDisplay4.Text = objHashTable["4"].ToString(); // ----------- Not Possible for HashTable ---------- //foreach (KeyValuePair<string, int> pair in objHashTable) //{ // lblDisplay.Text = pair.Value + " " + lblDisplay.Text; //} }
引用 dictionary :
public void MethodDictionary() { Dictionary<string, int> dictionary = new Dictionary<string, int>(); dictionary.Add("cat", 2); dictionary.Add("dog", 1); dictionary.Add("llama", 0); dictionary.Add("iguana", -1); //dictionary.Add(1, -2); // Compilation Error foreach (KeyValuePair<string, int> pair in dictionary) { lblDisplay.Text = pair.Value + " " + lblDisplay.Text; } }
原文：http://www.cnblogs.com/lthxk-yl/p/3553775.html