装箱、拆箱练习

【示例代码】

using System;
//Point is a Value Type
internal struct Point {
    private Int32 m_x, m_y;

    public Point(Int32 x,Int32 y){
        m_x = x;
        m_y = y;
    }

    public void Change(Int32 x, Int32 y){
        m_x = x;
        m_y = y;
    }

    public override String ToString(){
        return String.Format("({0}, {1})",m_x, m_y);
    }

    public sealed class Program {
        public static void Main(){
            Point p = new Point(1, 1);

            Console.WriteLine(p); //1,1 有装箱操作Console.WriteLine(Object)

            p.Change(2, 2);
            Console.WriteLine(p); //2,2 有装箱操作Console.WriteLine(Object)

            Object o = p; //有装箱操作
            Console.WriteLine(o); //2,2 无装箱
             
             ((Point) o).Change(3, 3); //拆箱并将Point对象复制到栈上临时变量中，并执行Change方法
             Console.WriteLine(o); //2,2
        }
    }
}