延迟循环使JFrame无法响应

Question

因此，当我运行此代码时，我的JFrame变得无响应。我设法将其追溯到gameLoop（）下的while循环。无论使用其中调用Thread.sleep（）的delay（1000
/ FRAMERATE），它都不允许键或鼠标侦听器执行其工作。

下面的完整代码，gameLoop（）中存在问题

package me.LemmingsGame;

import java.awt.*;
import java.awt.event.*;
import java.io.*;

import javax.swing.*;

public class Game extends JFrame implements KeyListener, MouseListener{

    private World wrld;//reference to current world
    private WorldFile loader=null;//world data

    private int gateCounter;

    private int width,height; //width and height of level

    private int mx,my;

    private int tool = Lemming.CLIMB;
    private Image dbImage; private Graphics dbg; //backbuffer  
    private Image [] sprites;//all images used in game

    private Lemming[] lemmings; //array of all Lemmings in level
    private int nextLem;//next Lemming to be received from Gate class

    private int running;//state of game
    private static final int FRAMERATE=180;//assigned framerate

    public Game(WorldFile loader){
        super("Lemmings");
        setLocation(50,40);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setResizable(false);
        width=3+loader.x*10;height=29+loader.y*10;
        loadImages();
        lemmings=new Lemming[loader.noLemmings*loader.gates().length];
        setSize(width,height);
        setVisible(true);   
        addMouseListener(this);
        addKeyListener(this);
        this.loader=loader;
        running=2;
        dbImage= createImage(width,height);
        dbg=dbImage.getGraphics();
        wrld=new World(loader,createImage(width,height), sprites, this);
        gameLoop();
    }
    public void loadImages(){
        sprites=new Image[2];
        sprites[0]=new ImageIcon("Resources/toolbar.png").getImage();
        sprites[1]=new ImageIcon("Resources/selector.png").getImage();
    }
    public static void delay(long len){
        try{
            Thread.sleep(len);
        }catch(InterruptedException e){
            System.out.println(e);
        }
    }
    public void moveLemmings(){
        if(nextLem>0)
            for(int i = 0;i<nextLem;i++)
                lemmings[i].cycle();
    }
    public void gameLoop(){

        wrld.openGates();
        while(running>0){
            delay(1000/FRAMERATE);
            if(running==2){
                gateCounter++;
                if(gateCounter>FRAMERATE*2){
                    wrld.cycleGates();
                    gateCounter=0;
                }
                moveLemmings();
                if(nextLem>0)
                    wrld.checkPositions(lemmings,nextLem);
            }
            repaint();
            //paint(getGraphics());
        }
    }
    public void paint(Graphics g){
        if(wrld!=null){
            dbg.setColor(Color.BLACK);
            dbg.fillRect(0, 0, width, height);
            wrld.draw(dbg);
            if(nextLem>0)
                for(int i=0;i<nextLem;i++){
                    lemmings[i].draw(dbg);
                }
            dbg.drawImage(sprites[0],0,0,null);
            dbg.drawImage(sprites[1],tool-3*39,0,null);
            g.drawImage(dbImage,3,29,this);
        }
    }
    public void addLemming(Lemming lemmy) {
        lemmings[nextLem]=lemmy;
        lemmy.spawn();
        nextLem++;
    }
    public void goal(){
        running=0;
        dispose();
        new Menu();
    }
    public void fail(){
        running=0;
        dispose();
        new Menu();
    }
    public void mouseClicked(MouseEvent e) {}
    public void mouseEntered(MouseEvent e) {}
    public void mouseExited(MouseEvent e) {}
    public void keyTyped(KeyEvent e) {}
    public void mousePressed(MouseEvent e) {
        System.out.println("boop");
        mx=e.getX();
        my=e.getY();
        if(my<40)
            if(mx<40)
                tool=Lemming.CLIMB;
            else if(mx>39&&mx<=39*2)
                tool=Lemming.CHUTE;

    }
    public void mouseReleased(MouseEvent arg0) {
        // TODO Auto-generated method stub

    }
    public void keyPressed(KeyEvent e) {
        System.out.println("boop2");
    }

    public void keyReleased(KeyEvent e) {

    }
}

如果很重要，程序将从此处开始，然后转到Game类

package me.LemmingsGame;

import java.awt.*;
import java.awt.event.*;
import java.io.File;

import javax.swing.*;

public class Menu extends JFrame implements ActionListener{
    /**
     * 
     */
    private static final long serialVersionUID = -1448646591011984524L;
    private JComboBox worldList;
    private JButton launch, worldEditor;
    private String [] worldPaths;
    private String [] worldNames;
    private int currentWorld;
    public Menu(){
        super("Lemmings! By: Jordan and Seth");
        this.setLocation(new Point(550,400));
        setResizable(false);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        File listDir[] = new File("./Worlds").listFiles();
        int x=0;
        for (int i = 0; i < listDir.length; i++) 
            if (listDir[i].isDirectory()) 
                   x++;
        worldPaths=new String[x];
        worldNames=new String[x];
        x=0;
        for (int i = 0; i < listDir.length; i++) 
            if (listDir[i].isDirectory()){ 
                    worldPaths[x]=listDir[i].getPath().substring(2);    
                    worldNames[x]=worldPaths[x].substring(7);
                    x++;
            }
        worldList=new JComboBox(worldNames);
        worldList.addActionListener(this);
        worldEditor=new JButton("Open World Editor");
        worldEditor.addActionListener(this);
        launch = new JButton("Play");
        launch.addActionListener(this);
        Container cp = getContentPane();
        cp.setLayout(new FlowLayout());
        cp.add(worldEditor);
        cp.add(worldList);
        cp.add(launch);
        pack();
        setVisible(true);
    }
    public void actionPerformed(ActionEvent e){
        if(e.getSource()==worldEditor){
            dispose();
            new MapEditor();
        }else if(e.getSource()==launch){
            dispose();
            try {
                new Game(new WorldFile(worldPaths[currentWorld]));
            } catch (Exception e1) {
                // TODO Auto-generated catch block
                e1.printStackTrace();
            }
        }else if(e.getSource()==worldList){
            currentWorld=worldList.getSelectedIndex();
        }
    }
    public static void main(String [] args){
        new Menu();
    }
}

可能无关紧要，但这是github存储库的插件https://github.com/cybnetsurfe3011/Lemmings-Computer-
Science/

Answer 1

您正在执行Thread.sleep()您的主线程，在这种情况下，即EDT（事件调度程序线程）。该线程负责绘制图形并收听事件。通过这样做，Thread.sleep()您实际上是在暂停它，因此不允许它完成任务。

看来您想每隔一段时间刷新一次GUI（至少这是我所猜测的）。如果是这种情况，则需要将逻辑移至新的单独线程，然后从产生的线程中调用所需的更新方法。若要使更改可见，您将需要使用SwingUtilities.invokeLater（）方法再次调用事件调度程序线程。