Question

有没有人曾经在加油站或杂货店使用过这些机器，你可以从中获得捐赠可回收物品的钱？好吧，我想制作一个虚拟的，到目前为止一切都没关系，直到我不得不做一些数学。我只有13岁，所以即使我觉得这很简单，这部分也很棘手。我需要可回收类型的价值乘以金额，然后加到总金额上。但是，不是将其添加到总钱中，而是将总数改为我添加的最近值。假设我添加2罐，即10美分，然后我再添加一罐，而不是总共15美分，我只需要5美分。希望你明白。我还想对我的代码进行一些建设性的批评。我知道这不是最好的，但我刚开始学习java，所以任何帮助都会很可爱。

    import java.awt.event.ActionEvent;
    import java.awt.event.ActionListener;
    import javax.swing.*;
    public class Machine {
    static JLabel label;
    static JComboBox typeList;
    static JComboBox amountList;
    public static void GUI(){

        JFrame frame = new JFrame("Recyclables Machine");
        frame.setVisible(true);
        frame.setSize(300,125);
        frame.setLocationRelativeTo(null);
        frame.setResizable(false);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JPanel panel = new JPanel();
        frame.add(panel);

        Integer[] amounts = {1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50};
        amountList = new JComboBox(amounts);
        panel.add(amountList);

        String[] types = {"Choose Recycable Type","Plastic Bottle","Can","2 Liter","Glass Bottle"};
        typeList = new JComboBox(types);
        panel.add(typeList);

        JButton button = new JButton("Add");
        panel.add(button);

        label = new JLabel("Total Money: 0 cents");
        panel.add(label);

        button.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent e){
                gettinItDone();
            }
        });
    }
    public static void gettinItDone(){
        String type = (String)typeList.getSelectedItem();
        int amount = (int)amountList.getSelectedItem();
        int money = 0;
        int temp = 0;

        if(type.equals("Plastic Bottle")){
            temp = 5 * amount;
            money = temp + money;
            label.setText("Total Money: "+ money +" cents");
        }else{
            if(type.equals("Can")){
                temp = 5 * amount;
                money = temp + money;
                label.setText("Total Money: "+ money +" cents");
            }else{
                if(type.equals("2 Liter")){
                    temp = 10 * amount;
                    money = temp + money;
                    label.setText("Total Money: "+ money +" cents");
                }else{
                    if(type.equals("Glass Bottle")){
                        temp = 10 * amount;
                        money = temp + money;
                        label.setText("Total Money: "+ money +" cents");
                    }else{
                        JOptionPane.showMessageDialog(null,"Invalid Recyclable Type", "Error", JOptionPane.ERROR_MESSAGE);
                    }
                }
            }
        }
    }
}

Answer 1

“money”变量的范围仅在事件侦听器触发时才有效。

button.addActionListener(new ActionListener(){
        public void actionPerformed(ActionEvent e){
            gettinItDone();
        }
    });

您需要将资金存储在#getIniitDone方法的范围之外。

数学“方程式”无法正常工作

1 个答案: