WeiBlog

class Program
{
public class Per
{
public void Say()
{
Console.WriteLine("Per");
}
}
public class PerSOne:Per
{
public void Say()
{
Console.WriteLine("PerSOne");
}
}
public class PerSTwo:Per
{
public void Say()
{
Console.WriteLine("PerSTwo");
}
}

    static void Main(string[] args)
    {
        //里式转换-类多态
        Per[] per = new Per[3];
        Random r = new Random();
        int rs = 0;
        for (int i = 0; i < per.Length; i++)
        {
            rs = r.Next(0, 2);
            switch(rs)
            {
                case 0:per[i] = new PerSOne();
                    break;
                case 1:per[i] = new PerSTwo();
                    break;
            }
        }

        for (int i = 0; i < per.Length; i++)
        {
            if (per[i] is PerSOne)
            {
                ((PerSOne)per[i]).Say();
            }
            else if (per[i] is PerSTwo)
            {
                ((PerSTwo)per[i]).Say();
            }
            else
                per[i].Say();
            
        }

        Console.ReadKey();

    }
   // 拆装箱的两种数据必须具有继承关系int-string非继承关系不会发生拆装箱