Question

我完成了这个项目的代码。但是我遇到按钮问题。出于某种原因，当我按下按钮时，我的速度和刹车都不起作用。 *速度文本框应显示速度为0，当我按下加速按钮它应该增加7，当我按下制动按钮它应该减少5.我不知道我做错了什么。这是我的课程的 Car.Java

dic = {}
fruit = 'apple'
vegetable = 'potato'

dic['fruit'] = fruit
dic['vegetable'] = vegetable

这是我的其他课 CarView ，我假设按钮不起作用

public class Car
{
    private String make;    //holds car make
    private int speed;      //holds car speed
    private int yearModel;  //holds year model

    //Costructor that will accept the year model as
    //an argument
    public Car(String mk, int ym)
    {
        this.yearModel = ym;
        this.make = mk;
        this.speed = 0;
    }

    //getYearModel accesor
    public int getYearModel()
    {
        return yearModel;
    }

    //getSpeed accesor
    public int getSpeed()
    {
        return speed;
    }

    //getMake accessor
    public String getMake()
    {
        return make;
    }

    //method for accelerate, this method is also additng 7(mph/km)
    public void accelerate()
    {
        speed += 7; // accelerate the speed counter by 7
    }

    //Method for brake, this method should subtract 5
    //from the current speed
    public void brake()
    {
        speed = speed - 5;
    }
}

任何帮助都将非常感谢

Answer 1

您实际上需要从Car获取状态值，并在更改时更新JTextField ...

accelerate.addActionListener(new ActionListener() 
    {
        @Override
        public void actionPerformed(ActionEvent e) 
        {
            //accelerating the car
            car.accelerate();
            speedText.setText(Integer.toString(car.getSpeed()));
        }
    });

现在做同样的事情打破

Answer 2

因为在更新回调中的支持字段时，您不会更新speedText。

你想做的事情如下：

 accelerate.addActionListener(new ActionListener() 
        {
            @Override
            public void actionPerformed(ActionEvent e) 
            {
                //accelerating the car
                car.accelerate();
                speedText.setText(Integer.toString(car.getSpeed()));
            }
        });

        brake.addActionListener(new ActionListener() 
        {
            @Override
            public void actionPerformed(ActionEvent e) 
            {
                //Apply brakes to the car
                car.brake();
                speedText.setText(Integer.toString(car.getSpeed()));
            }
        });

带按钮和GUI的Java

2 个答案: