class Program
    {      
        static void Main(string[] args)
        {
            //不是装拆箱   (类型转换)
            int n = 100;
            string s = Convert.ToString(n); //根据值在堆里创建，不是复制
            int m = int.Parse(s);
            //是装拆箱
            int x = 100;
            object o = x;
            int y = (int)o;
        }    
    }