继承ArrayList

 

    public class Attachments : ArrayList
    {
        /// <summary>
        /// 
        /// </summary>
        public Attachments()
        {
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="attachment"></param>
        /// <returns></returns>
        public int Add(Attachment attachment)
        {    
            return base.Add(attachment);
        }

        /// <summary>
        /// 
        /// </summary>
        public new Attachment this[int nIndex] 
        { 
            get{ return (Attachment)base[nIndex]; }

            set{ base[nIndex] = value; }
        }

    }

抄的