如何在jFrame中顯示大量的Graphics2D？

Question

我有一個jFrame（分辨率：300x300），並希望在其中顯示大量的橢圓。該字段的分辨率應該是4000x4000。我怎麼做？對於我創建的省略號字段，jComponent顯示所有500個省略號。

你會發現它只會顯示jComponent的一部分，如何調整jComponent以顯示所有的橢圓？

http://i.stack.imgur.com/75QA9.png

它我橢圓的面積/ JComponent的

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); 

     } 

    } 
} 

ANS這是我的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

你必須把你的JComponents到JPanel，這JPanel付諸JScrollPane

編輯：

@PeterGriffin寫道jScrollPane is nice, but i want to display all ellipes in this jFrame. That means the area (500 ellipses) should be scaled down to 300x300.

也許你會創建您Custom Paint到BufferedImage，這種形象付諸JComponent或Icon/ImageIcon到JLabel

例如：

從代碼：

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); 
      } 
     } 
    } 
} 

Answer 2

您可以轉換爲Graphics2D並使用scale（...）。在方法中傳遞300/4000（或任何您想要的大小和實際大小）。