c#數組去重的幾個算法

/// <summary>
       /// List泛型去重
       /// </summary>
       /// <param name="list">由一維數組組成的泛型</param>
       /// <param name="ItemID">要去除重復的項</param>
        private void RemoveRepeaterUrl(ref List<string[]> list,int ItemID)
        {
            for (int i = 0; i < list.Count; i++)
            {
                for (int j = (i + 1); j < list.Count; j++)
                {
                    if (list[j][ItemID] == list[i][ItemID])
                    {
                        list.RemoveAt(j);//去除相同的項
                        i = 0;//從新開始去重，如果數組內有大量重復的項，僅一次去重不能解決問題。這樣的用法會使效率慢1/3
                        j = 0;
                    }
                }
            }
        }