using System;
using System.Collections;
using System.Text;

namespace Zhaizj.Framework {

    /// <summary>
    /// 根据插入先后次序排序的 Hashtable
    /// </summary>
    public class Dictionary : Hashtable {

        private ArrayList _keys = new ArrayList();

        public Dictionary() {
        }

        /// <summary>
        /// 将键值插入字典
        /// </summary>
        /// <param name="key"></param>
        /// <param name="value"></param>
        public override void Add( Object key, Object value ) {
            base.Add( key, value );
            _keys.Add( key );
        }

        /// <summary>
        /// 设置字典的键值
        /// </summary>
        /// <param name="key"></param>
        /// <param name="value"></param>
        public void Set( Object key, Object value ) {
            base[key] = value;
            if (!_keys.Contains( key )) _keys.Add( key );
        }

        /// <summary>
        /// 清楚所有数据
        /// </summary>
        public override void Clear() {
            base.Clear();
            _keys.Clear();
        }

        /// <summary>
        /// 获取所有的 key（按照插入次序排序）
        /// </summary>
        public override ICollection Keys {
            get { return _keys; }
        }

        /// <summary>
        /// 删除某项
        /// </summary>
        /// <param name="key"></param>
        public override void Remove( Object key ) {
            base.Remove( key );
            _keys.Remove( key );
        }

        /// <summary>
        /// 根据 index 获取某项数据
        /// </summary>
        /// <param name="index"></param>
        /// <returns></returns>
        public Object Get( int index ) {
            Object key = _keys[index];
            return base[key];
        }


    }
}