c# 自定义 泛型集合Dictionary中 TValue值被改变的事件解决方法

c# 自定义 泛型集合Dictionary中 TValue值被改变的事件
如题，如何自定义集合Dictionary<TKey,TValue>中的 TValue值被改变的事件，

C# code

class CommandText    {        public ArrayList text { get; set; }        public Dictionary<string, string> textParams        {            get             {                return value;            }            set            {                if (textParams != value)                {                    Host();                    OnAssign();                }            }        }        private delegate void textParamsEventHandler();        private event textParamsEventHandler Assign;        public void OnAssign()        {            if (this.Assign != null)            {                Assign();            }        }        //注册事件        public void Host()        {            Assign += new textParamsEventHandler(StructText);        }        protected void StructText()        {            foreach (KeyValuePair<string, string> textParam in textParams)            {                //根据ROS命令规则，过滤第一条                for (int i = 1; i < text.Count; i++)                {                    //判断commandText是否存在该 参数                    int index = text[i].ToString().IndexOf(textParam.Key);                    if (index >= 0)                    {                        //获取旧值                        string old = text[i].ToString().Substring(index + 1, text[i].ToString().Length - index - 1);                        //替换新值                        text[i].ToString().Replace(old, textParam.Value);                    }                }            }        }    }

C# code

class DictionaryWapper<TKey, TValue>{    public class ValueChangedEventArgs<T> : EventArgs    {        public T Key { get; set; }        public ValueChangedEventArgs(T key)        {            Key = key;        }    }    private Dictionary<TKey, TValue> _dict;    public event EventHandler OnValueChanged;    public DictionaryWapper(Dictionary<TKey, TValue> dict)    {        _dict = dict;    }    public TValue this[TKey Key]    {        get { return _dict[Key]; }        set         {             if (!_dict[Key].Equals(value))             {                _dict[Key] = value;                OnValueChanged(this, new ValueChangedEventArgs<TKey>(Key));            }        }    }}