java - 当我拒绝访问子类属性时，怎么会这样？

class Casting
{
    main()
    {
        //instantiate the subclass MotoX
        CellPhone myPhone = new MotoX("motorola", "white", true, 5);
        MotoX phone = (MotoX) myPhone;
        //I tried to call MotoX methods using myPhone
        //however netbeans only showed the properties within the CellPhone class
    }
}

我知道降级转换可以将超类转换为更特定的子类型，但是当我这样做时，我无法访问MotoX类的属性。

最佳答案

myPhone被定义为CellPhone。如果要使用Motox方法，则应将其定义为Motox：

Motox myPhone = new MotoX("motorola", "white", true, 5);

或在使用时显式转换它：

CellPhone myPhone = new MotoX("motorola", "white", true, 5);
((Motox) myPhone).someMotoxMethod();