java - 如何在 jFrame 中显示大量 Graphics2D？

Question

我有一个 jFrame(分辨率:300x300)并希望在其中显示很多椭圆。该场分辨率应为 4000x4000。我怎么做？对于我创建的省略号字段，jComponent 显示所有 500 个省略号。

你看到它只会显示jComponent的一部分，如何调整jComponent的大小以显示所有省略号？

/image/75QA9.png

这是我的省略号/jComponent 区域

package home;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.geom.Ellipse2D;
import java.util.ArrayList;
import java.util.Random;

import javax.swing.JComponent;

public class Karte extends JComponent {

    private static final long serialVersionUID = 1L;
    int AMOUNT= 500;
    public ArrayList<Ellipse2D> Kreise = new ArrayList<Ellipse2D>();

    public Karte() {
        createCircles(AMOUNT);
    }

    private void createCircles(int AMOUNT) {
        Random r = new Random();
        for (int i = 1; i <= AMOUNT; i++) {
            Kreise.add(new Ellipse2D.Double(r.nextInt(4000), r.nextInt(4000), 4, 4));
        }

    }

    @Override
    protected void paintComponent(Graphics g) {


        Graphics2D kreis = (Graphics2D) g;       

        for (Ellipse2D t : Kreise) {

            kreis.setColor(Color.BLACK);
            kreis.draw(t);

        }

    }
}

这是我的 GUI

package home;

import java.awt.Dimension;
import java.awt.geom.Ellipse2D;
import java.util.ArrayList;

public class NewJFrame extends javax.swing.JFrame {

    private static final long serialVersionUID = 1L;

    public NewJFrame() {
        initComponents();

    }

    private void initComponents() {

        jLayeredPane1 = new javax.swing.JLayeredPane();
        karte1 = new home.Karte();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        javax.swing.GroupLayout karte1Layout = new javax.swing.GroupLayout(karte1);
        karte1.setLayout(karte1Layout);
        karte1Layout.setHorizontalGroup(karte1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.CENTER).addGap(0, 4000, Short.MAX_VALUE));
        karte1Layout.setVerticalGroup(karte1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.CENTER).addGap(0, 4000, Short.MAX_VALUE));

        karte1.setBounds(0, 0, 4000, 4000);
        karte1.setMinimumSize(new Dimension(300, 300));
        jLayeredPane1.add(karte1, javax.swing.JLayeredPane.DEFAULT_LAYER);

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).addComponent(jLayeredPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 300,
                Short.MAX_VALUE));
        layout.setVerticalGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).addComponent(jLayeredPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 300,
                Short.MAX_VALUE));

        pack();
    }

    public static void main(String args[]) {

        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Windows".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }

        java.awt.EventQueue.invokeLater(new Runnable() {

            public void run() {
                new NewJFrame().setVisible(true);
            }
        });
    }

    private javax.swing.JLayeredPane jLayeredPane1;
    private home.Karte karte1;

}

Answer 1

您必须将您的JComponents放入JPanel，这个JPanel放入JScrollPane

编辑:

@PeterGriffin 写道 jScrollPane 很好，但我想在这个 jFrame 中显示所有省略号。这意味着区域(500 个椭圆)应缩小到 300x300。

也许您会创建您的 Custom Paint到 BufferedImage，将此图像放入 JComponent 或作为 Icon/ImageIcon至 JLabel

例如:

来自代码:

import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
import javax.swing.SwingUtilities;
import javax.swing.Timer;
//http://stackoverflow.com/questions/3256269/jtextfields-on-top-of-active-drawing-on-jpanel-threading-problems/3256941#3256941
public class AnimationBackground {

    public AnimationBackground() {
        Random random = new Random();
        JFrame frame = new JFrame("Animation Background");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setResizable(false);
        frame.setLayout(new GridLayout(0, 1, 10, 10));
        JPanel fatherPanel = new JPanel();
        fatherPanel.setLayout(new GridLayout(0, 3, 10, 10));
        for (int iPanels = 0; iPanels < 3; iPanels++) {
            final MyJPanel panel = new MyJPanel();
            panel.setBackground(Color.BLACK);
            for (int i = 0; i < 100; i++) {
                Star star = new Star(new Point(random.nextInt(490), random.nextInt(490)));
                star.setColor(new Color(100 + random.nextInt(155), 100 + random.nextInt(155), 100 + random.nextInt(155)));
                star.setxIncr(-3 + random.nextInt(7));
                star.setyIncr(-3 + random.nextInt(7));
                panel.add(star);
            }
            panel.setLayout(new GridLayout(10, 1));
            JLabel label = new JLabel("This is a Starry background.", JLabel.CENTER);
            label.setForeground(Color.WHITE);
            panel.add(label);
            JPanel stopPanel = new JPanel();
            stopPanel.setOpaque(false);
            stopPanel.add(new JButton(new AbstractAction("Stop this madness!!") {

                private static final long serialVersionUID = 1L;

                @Override
                public void actionPerformed(ActionEvent e) {
                    panel.stopAnimation();
                }
            }));
            panel.add(stopPanel);
            JPanel startPanel = new JPanel();
            startPanel.setOpaque(false);
            startPanel.add(new JButton(new AbstractAction("Start moving...") {

                private static final long serialVersionUID = 1L;

                @Override
                public void actionPerformed(ActionEvent e) {
                    panel.startAnimation();
                }
            }));
            panel.add(startPanel);
            fatherPanel.add(panel);
        }
        JScrollPane scrollPane = new JScrollPane(fatherPanel);
        frame.add(scrollPane, BorderLayout.CENTER);
        frame.setSize(400, 300);
        frame.setLocation(150, 150);
        frame.setVisible(true);
    }

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

            @Override
            public void run() {
                AnimationBackground animationBackground = new AnimationBackground();
            }
        });
    }

    class Star extends Polygon {

        private static final long serialVersionUID = 1L;
        private Point location = null;
        private Color color = Color.YELLOW;
        private int xIncr, yIncr;
        static final int WIDTH = 500, HEIGHT = 500;

        Star(Point location) {
            int x = location.x;
            int y = location.y;
            this.location = location;
            this.addPoint(x, y + 8);
            this.addPoint(x + 8, y + 8);
            this.addPoint(x + 11, y);
            this.addPoint(x + 14, y + 8);
            this.addPoint(x + 22, y + 8);
            this.addPoint(x + 17, y + 12);
            this.addPoint(x + 21, y + 20);
            this.addPoint(x + 11, y + 14);
            this.addPoint(x + 3, y + 20);
            this.addPoint(x + 6, y + 12);
        }

        public void setColor(Color color) {
            this.color = color;
        }

        public void move() {
            if (location.x < 0 || location.x > WIDTH) {
                xIncr = -xIncr;
            }
            if (location.y < 0 || location.y > WIDTH) {
                yIncr = -yIncr;
            }
            translate(xIncr, yIncr);
            location.setLocation(location.x + xIncr, location.y + yIncr);
        }

        public void setxIncr(int xIncr) {
            this.xIncr = xIncr;
        }

        public void setyIncr(int yIncr) {
            this.yIncr = yIncr;
        }

        public Color getColor() {
            return color;
        }
    }

    class MyJPanel extends JPanel {

        private static final long serialVersionUID = 1L;
        private ArrayList<Star> stars = new ArrayList<Star>();
        private Timer timer = new Timer(20, new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                for (Star star : stars) {
                    star.move();
                }
                repaint();
            }
        });

        public void stopAnimation() {
            if (timer.isRunning()) {
                timer.stop();
            }
        }

        public void startAnimation() {
            if (!timer.isRunning()) {
                timer.start();
            }
        }

        @Override
        public void addNotify() {
            super.addNotify();
            timer.start();
        }

        @Override
        public void removeNotify() {
            super.removeNotify();
            timer.stop();
        }

        MyJPanel() {
            this.setPreferredSize(new Dimension(520, 520));
        }

        public void add(Star star) {
            stars.add(star);
        }

        @Override
        public void paintComponent(Graphics g) {
            super.paintComponent(g);
            ((Graphics2D) g).setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
            for (Star star : stars) {
                g.setColor(star.getColor());
                g.fillPolygon(star);
            }
        }
    }
}