Hashtable hashTable = new Hashtable();

//添加
hashTable.Add("web1", "mzwu.com");
hashTable.Add("web2", "163.com");
hashTable.Add("web3", "126.com");
hashTable.Add("web4", "sohu.com");
hashTable.Add("web5", "sina.com");

//检索
Response.Write(hashTable["web1"].ToString());

//遍历
foreach (DictionaryEntry item in hashTable)
{
    Response.Write(String.Format("{0},{1}<br/>", item.Key.ToString(), item.Value.ToString()));
}

//查找
string key = "web4";
if (hashTable.Contains(key)) Response.Write(hashTable[key].ToString());

//修改
hashTable["web2"] = "cnblogs.com";

//删除带有指定键的元素
hashTable.Remove("web3");

//删除所有元素
hashTable.Clear();