java - 当玩家第二次尝试时会攻击两次

Question

所以，当我第一次去战斗时，它会按预期进行，但之后当我再次去这个地方时，它会一次点击攻击老板两次，然后当我杀死他并去他那里时三次然后攻击boss三次，代码如下:

public class temp extends JFrame implements Runnable{

public static JPanel game=new JPanel();
public JPanel town_map=new JPanel(null);
public JPanel level1=new JPanel(null);
public JLabel character;
public Thread turn;
public JButton attack1=new JButton("reduce health");
public int health,healthleft;
public JLabel healthleftbl=new JLabel();

public boolean a=false;

CardLayout page= new CardLayout();

public static void main(String []args)
{
    new temp().setVisible(true);
}

public temp()
{
    super("Temporary Debug");
    setSize(640,510);
    setDefaultCloseOperation(EXIT_ON_CLOSE);

    game.setLayout(page);
    game.add(town_map,"map");
    game.add(level1, "lhealthleft1");
    add(game);
    town();
}

    public void town()
    {
        page.show(game, "map");
        JButton test=new JButton("Go to Battle");
        test.setBounds(0, 0, 150, 150);
        town_map.add(test);
        test.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent e)
            {
                level01();
            }
        });
    }   
    public void level01()
    {

        page.show(game, "lhealthleft1");
        attack1.setBounds(315, 368, 163, 57);
        health=800;
        healthleft=health;
        level1.add(attack1);
        healthleftbl.setBounds(150, 0, 100, 100);
        level1.add(healthleftbl);
       if(a==true)
        System.out.println(turn.getState());

        turn=new Thread(this);

        turn.start();
    }
        public void run() {
            a=true;
                attack1.addActionListener(new ActionListener()
                {
                    public void actionPerformed(ActionEvent e)
                    {
                            healthleft=healthleft-100;
                    }});

                do{
                healthleftbl.setText(healthleft+"/"+health);
                if(healthleft<=0)
                {
                    page.show(game, "map");
                    break;
                }
                System.out.println(healthleft);
                }while(turn.getState()!=null);
             }
}

Answer 1

您在重复自身的代码中添加 ActionListener，即被多次调用，这会导致在按下按钮时操作被多次调用。

public void run() {
    a = true;

    // **************************************
    // this add ActionListener gets called with every creation 
    // of a new Thread, and then calling .start() on the Thread
    attack1.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            healthleft = healthleft - 100;
        }
    });


    // **************************************
    // this code does not belong in an event-driven program
    do {
        healthleftbl.setText(healthleft + "/" + health);
        if (healthleft <= 0) {
            page.show(game, "map");
            break;
        }
        System.out.println(healthleft);
    } while (turn.getState() != null);
}

不要这样做。在程序设置期间添加一次 ActionListener，而不是在轮流期间添加。此外，您的 while (true) 循环不属于事件驱动程序，相反，您应该以状态模式模式化您的代码，其中程序的行为、对用户输入的响应、基于事件的变化程序的状态。

例如:

import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;

import javax.swing.*;
import javax.swing.event.SwingPropertyChangeSupport;

public class Temp2 extends JPanel {
    private CardLayout cardLayout = new CardLayout();
    private GamePanel gamePanel = new GamePanel(this);
    private IntroPanel introPanel = new IntroPanel(this);

    public Temp2() {
        setLayout(cardLayout);
        add(introPanel, IntroPanel.class.getName());
        add(gamePanel, GamePanel.class.getName());
    }

    public void showCard(String name) {
        cardLayout.show(this, name);
    }

    private static void createAndShowGui() {
        Temp2 mainPanel = new Temp2();

        JFrame frame = new JFrame("Temp2");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().add(mainPanel);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> createAndShowGui());
    }
}

@SuppressWarnings("serial")
class GamePanel extends JPanel {
    private static final int PREF_W = 400;
    private static final int PREF_H = 350;
    public static final int DAMAGE_AMOUNT = 100;
    private Temp2 temp2;
    private Player2 player2 = new Player2();
    private JLabel statusLabel = new JLabel();

    public GamePanel(Temp2 temp2) {
        this.temp2 = temp2;
        player2.addPropertyChangeListener(Player2.HEALTH, new PlayerListener());

        JPanel statusPanel = new JPanel(new FlowLayout(FlowLayout.LEADING, 5, 5));
        statusPanel.add(new JLabel("Health"));
        statusPanel.add(statusLabel);
        displayHealth();

        JPanel battlePanel = new JPanel(new GridBagLayout());
        battlePanel.add(new JButton(new BattleAction("Battle", KeyEvent.VK_B)));

        setLayout(new BorderLayout());
        add(statusPanel, BorderLayout.PAGE_START);
        add(battlePanel, BorderLayout.CENTER);
    }

    private void displayHealth() {
        String healthText = String.format("%03d/%03d", player2.getHealth(), Player2.MAX_HEALTH);
        statusLabel.setText(healthText);
    }

    public void reset() {
        player2.setHealth(Player2.MAX_HEALTH);
        temp2.showCard(IntroPanel.class.getName());
    }

    @Override
    public Dimension getPreferredSize() {
        if (isPreferredSizeSet()) {
            return super.getPreferredSize();
        }
        return new Dimension(PREF_W, PREF_H);
    }

    private class BattleAction extends AbstractAction {
        public BattleAction(String name, int mnemonic) {
            super(name);
            putValue(MNEMONIC_KEY, mnemonic);
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            int health = player2.getHealth() - DAMAGE_AMOUNT;
            player2.setHealth(health);
        }
    }

    private class PlayerListener implements PropertyChangeListener {
        @Override
        public void propertyChange(PropertyChangeEvent evt) {
            int health = (int) evt.getNewValue();
            displayHealth();
            if (health <= 0) {
                reset();
            }
        }
    }

}

@SuppressWarnings("serial")
class IntroPanel extends JPanel {
    private Temp2 temp2;

    public IntroPanel(Temp2 temp2) {
        this.temp2 = temp2;
        setLayout(new GridBagLayout());
        add(new JButton(new GoToBattleAction("Go To Battle", KeyEvent.VK_G)));
    }

    private class GoToBattleAction extends AbstractAction {
        public GoToBattleAction(String name, int mnemonic) {
            super(name);
            putValue(MNEMONIC_KEY, mnemonic);
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            temp2.showCard(GamePanel.class.getName());
        }
    }

}

class Player2 {
    // make health a "bound property" by using property change support and listeners
    public static final String HEALTH = "health";
    public static final int MAX_HEALTH = 800;
    private SwingPropertyChangeSupport pcSupport = new SwingPropertyChangeSupport(this);
    private int health;

    public Player2() {
        this.health = MAX_HEALTH;
    }

    public int getHealth() {
        return health;
    }

    // notify all listeners if health changes
    public void setHealth(int health) {
        int oldValue = this.health;
        int newValue = health;
        this.health = health;
        pcSupport.firePropertyChange(HEALTH, oldValue, newValue);
    }

    // allow outside code to listen for changes to all bound properties
    // should also have the associated remove listener methods too
    public void addPropertyChangeListener(PropertyChangeListener listener) {
        pcSupport.addPropertyChangeListener(listener);
    }

    public void addPropertyChangeListener(String name, PropertyChangeListener listener) {
        pcSupport.addPropertyChangeListener(name, listener);
    }

}