public static void ListCopy(IList<T> src, IList<T> dest)
        {
            if (src == null)
            {
                throw new System.ArgumentNullException("src", "src is null!");
            }

            if (dest == null)
            {
                throw new System.ArgumentNullException("dest", "dest is null!");
            }

            dest.Clear();

            foreach (T item in src)
            {
                dest.Add(item);
            }

        }

深拷贝吗？

有个简单的方法 

IList<string> list1 = new List<string>(); //源list

IList<string> list2 = new List<string>(list2); //目的list