Question

我有这样的事情：

public class Ship
{
    public void PositionX_pixels_set1(float _position_x){position_x = _position_x;}

    public class Engine : Ship
    {
        public int engines() { return 5; }
        public class Piston
        {
            public int pistons(){return 5;}
        }
    }

}


void Main
{
    Ship ship = new Ship()
    int a = ship.Engine.Piston.pistons;//why this not working?
}

我不知道我做错了什么。为什么“ship.Engine.Piston.pistons”不工作？

Answer 1

因为Engine类中的Ship 类型及其成员。

要解决此问题，可以执行以下操作：

public class Ship
{
    public void PositionX_pixels_set1(float _position_x){position_x = _position_x;}

    private void Engine _myEngine = new Engine(); //DEFINE ENGINE MEMBER

    public Engine MyEngine {   //DEFINE A PROPERTY TO ACCESS THAT MEMBER
        get {
           return _myEngine;
        }
    }

    public class Engine : Ship
    {
        public int engines() { return 5; }
        private Piston _myPiston = new Piston();//DEFINE PISTON MEMBER

        public Piston MyPiston {//DEFINE A PROPERTY TO ACCESS THAT 
           get {
               return _myPiston ;
           }
        }

        public class Piston
        {
            public int pistons(){return 5;}
        }

       MEMBER
    }

}

使用后就像：

int a = ship.MyEngine.MyPiston.pistons

Answer 2

您必须启动子类型的对象（嵌套类型）才能访问其方法，如果您没有创建嵌套类型的任何对象，则无法访问其方法。

在您创建new Ship()时，您没有创建任何Engine或Piston，因此您无法访问非现有对象的方法Pistons()。

基本类 - 嵌套类

2 个答案: