当另一个 class 的变量发生变化时，如何更新 JLabel 文本？

Question

我有GUI class ，其中通过单击Pick_Flowers class的JButton pick_flower实例创建并通过单击Alchemy class的JButton make_fuel实例创建。 我想单击一次按钮，然后文本将根据现在的值（鲜花总和或燃料总和）而改变。 例如，花 5 秒后总和将为 3（因此 JLabel 的文本将为“3”），10 秒后总和将为 6（因此 JLabel 的文本将为“6”）等等。但在我的 GUI 文本中JLabel 没有改变（鲜花总是“3”）。

public class GUI extends JFrame {

public static void main(String args[]) {
    GUI g = new GUI();
}

public GUI() {
    JFrame frame = new JFrame("Worker");
    JPanel panel = new JPanel();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setExtendedState(JFrame.MAXIMIZED_BOTH);
    frame.setVisible(true);
    panel.setLayout(null);
    frame.add(panel);

    JLabel flower_count = new JLabel("0 flowers");
    panel.add(flower_count);
    Dimension flower_count_size = flower_count.getPreferredSize();
    flower_count.setBounds(800, 125, 200, flower_count_size.height);

    JLabel fuel_count = new JLabel("0 fuel");
    panel.add(fuel_count);
    Dimension fuel_count_size = fuel_count.getPreferredSize();
    fuel_count.setBounds(800, 275, 200, fuel_count_size.height);

    JButton pick_flower = new JButton("Pick flowers");
    panel.add(pick_flower);
    pick_flower.setBounds(600, 110, 130, 60);

    pick_flower.addActionListener(v -> {
        Pick_Flowers pick_flowers = new Pick_Flowers();
        flower_count.setText(android_helper.sum(pick_flowers.flowers)) + " flowers picked");

    });

    JButton make_fuel = new JButton("Extract fuel");
    panel.add(make_fuel);
    make_fuel.setBounds(600, 250, 160, 60);

    make_fuel.addActionListener(mi -> {
        Alchemy alchemy = new Alchemy();
        fuel_count.setText(android_helper.sum(alchemy.fuel_tanks) + " fuel extracted");
    });

    frame.setVisible(true);
}

     } 

这是Pick_Flower class ：

     import java.util.*;

     public class Pick_Flowers {

GirlsList girlsList = new GirlsList();
List<Integer> flowers = new ArrayList<>();
Android_Helper android_helper = new Android_Helper();

public static void main(String[] args) {

}

public Pick_Flowers(){
    Timer t = new Timer();
    t.schedule(new TimerTask() {
        @Override public void run() {
            flowerPicker();
        }
    }, 0, 5000);

}

public int flowerPicker() {
    int flower_picked = 1 * girlsList.flower_girls.size();
    flowers.add(flower_picked);
    System.out.println(android_helper.sum(flowers));
    return android_helper.sum(flowers);
}
      }

和Alchemy class

import java.util.*;

public class Alchemy{

GirlsList girlsList = new GirlsList();
List<Integer> fuel_tanks = new ArrayList<>();
Pick_Flowers w = new Pick_Flowers();
Android_Helper android_helper = new Android_Helper();

public static void main(String[] args) {

}

public Alchemy(){
    Timer t = new Timer();
    t.schedule(new TimerTask() {
        @Override public void run() {
           alchemyFuel();
        }
    }, 0, 15000);
}

public int alchemyFuel(){
    int flower_sum = android_helper.sum(w.flowers);
    System.out.println(flower_sum);
    int fuel = (flower_sum / girlsList.flower_girls.size()) * girlsList.alchemy_girls.size();
    fuel_tanks.add(fuel);
    int now_flowers = flower_sum - fuel;
    w.flowers = new ArrayList<>();
    w.flowers.add(now_flowers);
    return android_helper.sum(fuel_tanks);
} 
    }

Answer 1

每次按下按钮时，您都会创建新的 Pick_Flowers，因此鲜花列表每次都是新的。 将 Pick_Flowers 存储在侦听器外部的变量中。 炼金术也是如此。