c#遍历HashTable

Hashtable hashTable = new Hashtable();
            hashTable.Add(1, "wuyi");
            hashTable.Add(2, "sky");
            System.Windows.Forms.MessageBox.Show((string)hashTable[1]);
            foreach (DictionaryEntry de in hashTable)
            {
                System.Windows.Forms.MessageBox.Show(de.Key.ToString());
                System.Windows.Forms.MessageBox.Show(de.Value.ToString());
            }
            System.Collections.IDictionaryEnumerator enumerator = hashTable.GetEnumerator();
            while (enumerator.MoveNext())
            {
                 System.Windows.Forms.MessageBox.Show(enumerator.Key.ToString());
                System.Windows.Forms.MessageBox.Show( enumerator.Value.ToString());
            }
            return (string)hashTable[1];