hashtable和arraylist（转载）

实现在外部给hashtable排序

using System;

using System.Collections.Generic;

using System.Text;

using System.Collections;

namespace MyClassLibrary

{

public class MyHashtable : Hashtable

{

private ArrayList _MyKeys = new ArrayList();

public MyHashtable()

{

}

public override void Add(object key, object value)

{

base.Add(key, value);

_MyKeys.Add(key);

}

public override ICollection Keys

{

get

{

return Keys;

}

}

public ICollection MyKeys

{

get

{

return _MyKeys;

}

}

public override void Clear()

{

base.Clear();

_MyKeys.Clear();

}

public override void Remove(object key)

{

base.Remove(key);

_MyKeys.Remove(key);

}

public override IDictionaryEnumerator GetEnumerator()

{

return base.GetEnumerator();

}

}

}

private void SortHashtable()

{

MyHashtable ht = new MyHashtable();

ht.Add(DateTime.Now.AddDays(1).ToString(), "1");

ht.Add(DateTime.Now.AddDays(2).ToString(), "2");

ht.Add(DateTime.Now.AddDays(3).ToString(), "3");

ht.Add(DateTime.Now.AddDays(4).ToString(), "4");

ht.Add(DateTime.Now.AddDays(5).ToString(), "5");

foreach (string str in ht.MyKeys)

{

this.DropDownList1.Items.Add(new ListItem(str, ht[str].ToString()));

}

this.DropDownList1.DataBind();

}