Java图形签出模拟; [英] Java Graphics Checkout Simulation;

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本文介绍了Java图形签出模拟;的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

我正在开发一个Checkout Simulation项目。我有让代码正常运行的代码，但是我一直在努力理解和实现如何在一定条件成立时添加图形（在我的情况下是方形）。例如，我编写了我的代码，以便通过随机数字，如果2,4,6或8是随机生成的，则会将某人添加到队列中，并且如果它们是偶数1或3，从队列中移除。我基本上只是想知道如何在屏幕上添加一个正方形（例如，生成一个4应该在屏幕上添加一个方块，但它不会）
任何帮助真的会被赞赏！


$ b public class MainPanel extends JPanel {

  private Queue< String> tillQueue; 
 private int rndNumber; 
 private int currentLength; 
 private ArrayList< Integer> lengthList; 
私人双重均值; 
 private随机rand; 
 private int MAXLENGTH; 
 
 private static Random r = new Random（）; 
 private static Random r2 = new Random（）; 
颜色的颜色; 
 private static final int IMAGE_SIZE = 600; 
 
私人定时器定时器; 
 private int delay; 
 
私人JButton startButton; 
私人JButton stopButton; 
专用BufferedImage缓冲区; 
 JToolBar工具栏; 
 
 public MainPanel（）{
 startButton = new JButton（START）; 
 stopButton = new JButton（STOP）; 
 toolbar = new JToolBar（）; 
 toolbar.add（startButton）; 
 toolbar.add（stopButton）; 
 
 this.buffer = new BufferedImage（IMAGE_SIZE，IMAGE_SIZE，BufferedImage.TYPE_INT_ARGB）; 
 setDoubleBuffered（false）; 
 
 StartActionHandler start = new StartActionHandler（）; 
 StopActionHandler stop = new StopActionHandler（）; 
 TimerEvent timerEvt = new TimerEvent（）; 
 
 startButton.addActionListener（start）; 
 stopButton.addActionListener（stop）; 
 delay = 50; 
 timer = new Timer（delay，timerEvt）; 
 
 
 public class TimerEvent implements ActionListener {
 
 public void actionPerformed（ActionEvent e）{
 // drawNext（buffer.getGraphics（））; （int time = 1; time <9; time ++）{
 rndNumber = rand.nextInt（6）+1; 
 
; //产生随机数
 
 if（rndNumber == 2 || rndNumber == 4 || rndNumber == 6 || rndNumber == 8）{
 //将时间添加到队列中
 untilQueue.add（String.valueOf（time））; 
 drawNext（buffer.getGraphics（））; 
 repaint（）; 
 
 
 
 
 $ b public class StartActionHandler实现ActionListener {
 
 public void actionPerformed（ActionEvent e）{ 
 timer.start（）; 
 
 
 
 private void drawNext（Graphics g）{
 int x = r.nextInt（IMAGE_SIZE）; 
 int y = r.nextInt（IMAGE_SIZE）; 
 int red = r2.nextInt（255）; 
 int green = r2.nextInt（255）; 
 int blue = r2.nextInt（255）; 
颜色randomColour =新颜色（红色，绿色，蓝色）; 
 g.setColor（randomColour）; 
 g.fillRect（x，y，10，10）; 
 repaint（）; 
} 
 
保护void paintComponent（Graphics g）{
 super.paintComponent（g）; 
 g.drawImage（buffer，0，0，this）; 
} 
}


解决方案

为了方便，使用缓冲区的 createGraphics（） c $ c>方法和 dispose（）完成。 初始化屏幕外的 buffer 为一个已知状态。

  • 一个随机通常是足够的。


  • 尽可能限制变量范围，例如 private class TimerEvent 。


  • 覆盖 getPreferredSize（） 以建立渲染区域大小。






    • 经测试：

      import java.awt.BorderLayout; 
     import java.awt.Color; 
     import java.awt.Dimension; 
     import java.awt.EventQueue; 
     import java.awt.Graphics; 
     import java.awt.Graphics2D; 
     import java.awt.event.ActionEvent; 
     import java.awt.event.ActionListener; 
     import java.awt.image.BufferedImage; 
     import java.util.LinkedList; 
     import java.util.Queue; 
     import java.util.Random; 
     import javax.swing.ImageIcon; 
     import javax.swing.JButton; 
     import javax.swing.JFrame; 
     import javax.swing.JLabel; 
     import javax.swing.JPanel; 
     import javax.swing.JToolBar; 
     import javax.swing.Timer; 
     
     / ** 
     * @ https https://stackoverflow.com/a/21238669/230513 
     * / 
     public class Test {
     
     private void display（）{
     JFrame f = new JFrame（Test）; 
     f.setDefaultCloseOperation（JFrame.EXIT_ON_CLOSE）; 
     f.add（new MainPanel（））; 
     f.pack（）; 
     f.setLocationRelativeTo（null）; 
     f.setVisible（true）; 
     
     
     public static void main（String [] args）{
     EventQueue.invokeLater（new Runnable（）{
     $ b $ @Override 
     public void run（）{
     new Test（）。display（）; 
    } 
    }）; 
    } 
     
     private static class MainPanel extends JPanel {
     
     private static final int SIZE = 500; 
     private static final int DELAY = 100; 
     private static final Random r = new Random（）; 
     private final Queue< String> untilQueue = new LinkedList<>（）; 
    私人定时器定时器; 
    私人JButton startButton; 
    私人JButton stopButton; 
    专用BufferedImage缓冲区; 
    私人JToolBar工具栏; 
     
     public MainPanel（）{
     super（new BorderLayout（））; 
     startButton = new JButton（START）; 
     stopButton = new JButton（STOP）; 
     toolbar = new JToolBar（）; 
     toolbar.add（startButton）; 
     toolbar.add（stopButton）; 
     buffer = new BufferedImage（SIZE，SIZE，BufferedImage.TYPE_INT_ARGB）; 
     Graphics2D g = buffer.createGraphics（）; 
     g.clearRect（0，0，SIZE，SIZE）; 
     g.dispose（）; 
     StartActionHandler start = new StartActionHandler（）; 
     TimerEvent timerEvt = new TimerEvent（）; 
     timer = new Timer（DELAY，timerEvt）; 
     startButton.addActionListener（start）; 
     add（new JLabel（new ImageIcon（buffer）））; 
     add（工具栏，BorderLayout.SOUTH）; 
     
     $ b $ private class TimerEvent implements ActionListener {
     $ b $ @Override 
     public void actionPerformed（ActionEvent e）{
     for（int time = 1; time <9; time ++）{
     if（r.nextInt（6）％2 == 0）{
     untilQueue.add（String.valueOf（time））; 
     drawNext（）; 
     
     
     
     
     $ b Private class StartActionHandler实现了ActionListener {
     
     @Override 
     public void actionPerformed（ActionEvent e）{
     timer.start（）; 
     
     
     
     private void drawNext（）{
     Graphics2D g = buffer.createGraphics（）; 
     int x = r.nextInt（SIZE）; 
     int y = r.nextInt（SIZE）; 
     g.setColor（new Color（r.nextInt（）））; 
     g.fillRect（x，y，10，10）; 
     g.dispose（）; 
     repaint（）; 
     
     
     @Override 
     protected void paintComponent（Graphics g）{
     super.paintComponent（g）; 
     g.drawImage（buffer，0，0，this）; 
     
     $ b @Override 
     public Dimension getPreferredSize（）{
     return new Dimension（SIZE，SIZE）; 
    } 
    } 
    }


    I am working on a project which is a Checkout Simulation. I have the code to make it work run but i am struggling to understand and implement how to add graphics(in my case a square) once a certain condition is true. For example i have made my code so that it goes through random numbers and if 2,4,6 or 8 has been randomly generated, someone will be added to the queue and the same goes for if they are even numbers 1 or 3, someone is removed from the queue. I basically just want to know how to add a square to the screen once i have met my condition (for example, generating a 4 should add a square to the screen but it doesn't) ANY help would really be appreciated!

    public class MainPanel extends JPanel {

        private Queue<String> tillQueue;
    private int rndNumber;
    private int currentLength;
    private ArrayList<Integer> lengthList;
    private double mean;
    private Random rand;
    private int MAXLENGTH;

    private static Random r = new Random();
    private static Random r2 = new Random();
    Color colour;
    private static final int IMAGE_SIZE = 600;

    private Timer timer;
    private int delay;

    private JButton startButton;
    private JButton stopButton;
    private BufferedImage buffer;
    JToolBar toolbar;

    public MainPanel() {
        startButton = new JButton("START");
        stopButton = new JButton("STOP");
        toolbar = new JToolBar();
        toolbar.add(startButton);
        toolbar.add(stopButton);

        this.buffer = new BufferedImage(IMAGE_SIZE, IMAGE_SIZE, BufferedImage.TYPE_INT_ARGB);
        setDoubleBuffered(false);

        StartActionHandler start = new StartActionHandler();
        StopActionHandler stop = new StopActionHandler();
        TimerEvent timerEvt = new TimerEvent();

        startButton.addActionListener(start);
        stopButton.addActionListener(stop);
        delay = 50;
        timer = new Timer(delay, timerEvt);
    }

    public class TimerEvent implements ActionListener {

        public void actionPerformed(ActionEvent e) {
            //drawNext(buffer.getGraphics());

            for (int time = 1; time < 9; time++) {
                rndNumber = rand.nextInt(6) + 1; //generates random number

                if (rndNumber == 2 || rndNumber == 4 || rndNumber == 6 || rndNumber == 8) {
                    //time is added to queue                        
                    tillQueue.add(String.valueOf(time));
                    drawNext(buffer.getGraphics());
                    repaint();
                }
            }
        }
    }

    public class StartActionHandler implements ActionListener {

        public void actionPerformed(ActionEvent e) {
            timer.start();
        }
    }

    private void drawNext(Graphics g) {
        int x = r.nextInt(IMAGE_SIZE);
        int y = r.nextInt(IMAGE_SIZE);
        int red = r2.nextInt(255);
        int green = r2.nextInt(255);
        int blue = r2.nextInt(255);
        Color randomColour = new Color(red, green, blue);
        g.setColor(randomColour);
        g.fillRect(x, y, 10, 10);
        repaint();
    }

    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        g.drawImage(buffer, 0, 0, this);
    }
}

    解决方案

    Note several changes to get rendering working:

    • For convenience, use the buffer's createGraphics() method and dispose() it when done.

    • Initialize the offscreen buffer to a known state.

    • One instance of Random is usually sufficient.

    • Limit variable scope to the extent possible, e.g. private class TimerEvent.

    • Override getPreferredSize() to establish the rendering area size.

    As tested:

    import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.util.LinkedList;
import java.util.Queue;
import java.util.Random;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JToolBar;
import javax.swing.Timer;

/**
 * @see https://stackoverflow.com/a/21238669/230513
 */
public class Test {

    private void display() {
        JFrame f = new JFrame("Test");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.add(new MainPanel());
        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                new Test().display();
            }
        });
    }

    private static class MainPanel extends JPanel {

        private static final int SIZE = 500;
        private static final int DELAY = 100;
        private static final Random r = new Random();
        private final Queue<String> tillQueue = new LinkedList<>();
        private Timer timer;
        private JButton startButton;
        private JButton stopButton;
        private BufferedImage buffer;
        private JToolBar toolbar;

        public MainPanel() {
            super(new BorderLayout());
            startButton = new JButton("START");
            stopButton = new JButton("STOP");
            toolbar = new JToolBar();
            toolbar.add(startButton);
            toolbar.add(stopButton);
            buffer = new BufferedImage(SIZE, SIZE, BufferedImage.TYPE_INT_ARGB);
            Graphics2D g = buffer.createGraphics();
            g.clearRect(0, 0, SIZE, SIZE);
            g.dispose();
            StartActionHandler start = new StartActionHandler();
            TimerEvent timerEvt = new TimerEvent();
            timer = new Timer(DELAY, timerEvt);
            startButton.addActionListener(start);
            add(new JLabel(new ImageIcon(buffer)));
            add(toolbar, BorderLayout.SOUTH);
        }

        private class TimerEvent implements ActionListener {

            @Override
            public void actionPerformed(ActionEvent e) {
                for (int time = 1; time < 9; time++) {
                    if (r.nextInt(6) % 2 == 0) {
                        tillQueue.add(String.valueOf(time));
                        drawNext();
                    }
                }
            }
        }

        private class StartActionHandler implements ActionListener {

            @Override
            public void actionPerformed(ActionEvent e) {
                timer.start();
            }
        }

        private void drawNext() {
            Graphics2D g = buffer.createGraphics();
            int x = r.nextInt(SIZE);
            int y = r.nextInt(SIZE);
            g.setColor(new Color(r.nextInt()));
            g.fillRect(x, y, 10, 10);
            g.dispose();
            repaint();
        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            g.drawImage(buffer, 0, 0, this);
        }

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(SIZE, SIZE);
        }
    }
}

    这篇关于Java图形签出模拟;的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！

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