按下Jbutton后JFrame冻结

Question

I have been having a problem with my JFrame . I have added five JButtons for a user interface for an rpg program that I'm working on. When the "Status" button is pressed, the JFrame freezes, and nothing, not even EXIT_ON_CLOSE works. I want to know how to get the status button to work, and how to avoid this problem with any of the other buttons.

Here's the ButtonListener class:

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.SwingUtilities;


public class ButtonListeners {
public static final int WIDTH=360;
public static final int HEIGHT=360;
final static Monsters sk = new Monsters("Skeleton",120,20,30,5,50);
final static Monsters dm = new Monsters("Dark Mage",130,10,40,10,100);
final static Monsters kn = new Monsters("Knight",160,30,40,2,120);
final static Monsters sm = new Monsters("Slime",200,1,50,5,150);
final static Monsters go = new Monsters("golem",500,50,55,15,400);
final static Monsters dg = new Monsters("dragon",1000,35,100,25,600);
final static Monsters bk = new Monsters("Black Knight",2000,35,90,12,1000);
final static Monsters zm = new Monsters("Zombie",100,30,35,5,50);
public static void UI(){
    final JFrame frame=new JFrame("Guantlet");
    frame.setSize(800,600);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    final Player p = new Player();
    frame.setSize(WIDTH,HEIGHT);
    final JButton item = new JButton("Items");
    final JButton status=new JButton("Status");
    final JButton attack=new JButton("Attack");
    final JButton defend = new JButton("Defend");
    final JButton mStat = new JButton("Monster Status");
    frame.setVisible(true);
    frame.add(attack,BorderLayout.EAST);
    frame.add(defend,BorderLayout.WEST);
    frame.add(item, BorderLayout.NORTH);
    frame.add(status, BorderLayout.SOUTH);
    frame.add(mStat, BorderLayout.CENTER);

    final ArrayList<Monsters> monOrder = new ArrayList<Monsters>();
    monOrder.add(0,sk);
    monOrder.add(1,zm);
    monOrder.add(2,kn);
    monOrder.add(3,sm);
    monOrder.add(4,dm);
    monOrder.add(5,go);
    monOrder.add(6,dg);
    monOrder.add(7,bk);
    frame.setVisible(true);
    JOptionPane.showMessageDialog(frame, "Welcome to the arena! Many opponents await.");

    JOptionPane.showMessageDialog(frame,"A Skeleton draws near!");

    class Button1Listener implements ActionListener{


        @Override
        public void actionPerformed(ActionEvent e) {
            boolean battle1 = true;

            while(battle1){

                if(e.getSource() == attack){// &&monOrder.contains(sk) && monOrder.contains(zm) && monOrder.contains(kn) && monOrder.contains(dm) && monOrder.contains(go) && monOrder.contains(dg)&& monOrder.contains(bk)) {
                    if(monOrder.contains(sk)){


                        sk.mHP=sk.mHP-sk.attacked(p);
                        sk.status();
                        sk.isAlive();
                        if(sk.isAlive()){
                            p.hp=p.hp-sk.attacking(p);
                            System.out.println("The Skeleton has "+sk.mHP+" health left");
                            System.out.println("You have "+"You have "+p.hp+ " health left");
                            p.status();
                        }else if(!sk.isAlive()){
                            monOrder.remove(0);
                            p.exp=p.exp+sk.exp;
                            p.levelUp();
                            JOptionPane.showMessageDialog(frame,"A Zombie emerges!");

                        }
                        //}



                        System.out.println(zm.mHP);

                    }
                    if(monOrder.contains(zm) && !monOrder.contains(sk)){
                        zm.mHP=zm.mHP-zm.attacked(p);

                        zm.status();

                        zm.isAlive();
                        if(zm.isAlive()){
                            p.hp=p.hp-zm.attacking(p);
                            System.out.println("The Skeleton has "+zm.mHP+" health left");
                            System.out.println("You have "+"You have "+p.hp+ " health left");
                            p.status();
                        }else if(!zm.isAlive()){
                            monOrder.remove(0);
                            p.exp=p.exp+zm.exp;
                            p.levelUp();
                            JOptionPane.showMessageDialog(frame,"A Dark Mage appears before you!");

                        }
                    }
                    break;
                }
            }


        }

    }

    ActionListener b1L=new Button1Listener();

    attack.addActionListener(b1L);

    status.addActionListener(b1L);

    status.addActionListener(new ActionListener() { 
        @Override
        public void actionPerformed(ActionEvent e) {
            if(e.getSource() == status ){

                JOptionPane.showMessageDialog(frame, "Maximum Health = " + p.maxHP+" \n Strength = " + p.str + "\n Speed = "+p.spd+"\n Experience to next level- "+(p.reqExp-p.exp));
                Thread t = new Thread(new Runnable() {
                    public void run() {

                        // execute query here

                        SwingUtilities.invokeLater(new Runnable() {
                            public void run() {

                                // update the ui here
                                final JFrame frame=new JFrame("Guantlet");
                                frame.setSize(800,600);
                                frame.add(attack,BorderLayout.EAST);
                                frame.add(defend,BorderLayout.WEST);
                                frame.add(item, BorderLayout.NORTH);
                                frame.add(status, BorderLayout.SOUTH);
                                frame.add(mStat, BorderLayout.CENTER);

                            }
                        });
                    }
                });
                t.start();
            }
        }

    });
}
}

Answer 1

You've got a long-running bit of code here:

while(battle1){
  //....
}

and since this is running in the Swing event thread, it is tying up the event thread, freezing your application. The solution is to avoid doing this, avoid tying up the event thread. Possible solutions depend on your needs including use of a Swing Timer for a game loop, use of a background Thread for long-running processes, or re-constructing your code so that this while loop isn't needed.

A quick review of your code suggests that perhaps you would want to go the Swing Timer route. If you Google Java Swing Timer tutorial you'll get decent info on using this.

---

As an aside, you are over-using the static modifier and should fix this. You should use this only sparingly and only for specific needs.

---

Aside number 2: look into the MVC or Model-View-Control design pattern as a way to separate your game logic out of your GUI. You've got them mixed together in a way that will make extending, improving and debugging your program difficult.

Answer 2

Why are you using while(true) an infinite loop whereas you have called break statement in a condition. what happened if condition is not matched? Please look it again as shown below.

while(battle1){
    if(e.getSource() == attack){
        ...
        break;
    }
}

When status button is clicked then if(e.getSource() == attack) will never be matched and your program will go in infinite loop.