JPanel里面的JPanel

2 回答

• 4

  不要使用静态变量 .

  不要使用null布局 .

  使用适当的布局管理器也许主面板使用BorderLayout . 然后将主要组件添加到CENTER，将第二个面板添加到EAST . 第二个面板也可以使用BorderLayout . 然后，您可以根据需要将两个组件添加到NORTH，CENTER或SOUTH .

  回复于 2024-04-28T01:05:38+08:00
• 1

  例如，使用自定义边框：

  import java.awt.BorderLayout;
  import java.awt.Color;
  import java.awt.Component;
  import java.awt.Dimension;
  import java.awt.Graphics;
  import java.awt.Graphics2D;
  import java.awt.GridLayout;
  import java.awt.Insets;
  import java.awt.RadialGradientPaint;
  import java.awt.geom.Point2D;
  import java.awt.image.BufferedImage;
  import java.io.IOException;
  import java.net.MalformedURLException;
  import java.net.URL;
  
  import javax.imageio.ImageIO;
  import javax.swing.*;
  import javax.swing.border.AbstractBorder;
  
  @SuppressWarnings("serial")
  public class FrameEg extends JPanel {
     public static final String FRAME_URL_PATH = "http://th02.deviantart.net/"
           + "fs70/PRE/i/2010/199/1/0/Just_Frames_5_by_ScrapBee.png";
     public static final int INSET_GAP = 120;
  
     private BufferedImage frameImg;
     private BufferedImage smlFrameImg;
  
     public FrameEg() {
        try {
           URL frameUrl = new URL(FRAME_URL_PATH);
           frameImg = ImageIO.read(frameUrl);
  
           final int smlFrameWidth = frameImg.getWidth() / 2;
           final int smlFrameHeight = frameImg.getHeight() / 2;
           smlFrameImg = new BufferedImage(smlFrameWidth, smlFrameHeight,
                 BufferedImage.TYPE_INT_ARGB);
           Graphics g = smlFrameImg.getGraphics();
           g.drawImage(frameImg, 0, 0, smlFrameWidth, smlFrameHeight, null);
           g.dispose();
  
           int top = INSET_GAP;
           int left = top;
           int bottom = top;
           int right = left;
           Insets insets = new Insets(top, left, bottom, right);
           MyBorder myBorder = new MyBorder(frameImg, insets);
  
           JTextArea textArea = new JTextArea(50, 60);
           textArea.setWrapStyleWord(true);
           textArea.setLineWrap(true);
           for (int i = 0; i < 300; i++) {
              textArea.append("Hello world! How is it going? ");
           }
           setLayout(new BorderLayout(1, 1));
           setBackground(Color.black);
  
           Dimension prefSize = new Dimension(frameImg.getWidth(),
                 frameImg.getHeight());
           JPanel centerPanel = new MyPanel(prefSize);
           centerPanel.setBorder(myBorder);
           centerPanel.setLayout(new BorderLayout(1, 1));
           centerPanel.add(new JScrollPane(textArea), BorderLayout.CENTER);
  
           MyPanel rightUpperPanel = new MyPanel(new Dimension(smlFrameWidth,
                 smlFrameHeight));
           MyPanel rightLowerPanel = new MyPanel(new Dimension(smlFrameWidth,
                 smlFrameHeight));
           top = top / 2;
           left = left / 2;
           bottom = bottom / 2;
           right = right / 2;
           Insets smlInsets = new Insets(top, left, bottom, right);
           rightUpperPanel.setBorder(new MyBorder(smlFrameImg, smlInsets));
           rightUpperPanel.setLayout(new BorderLayout());
           rightLowerPanel.setBorder(new MyBorder(smlFrameImg, smlInsets));
           rightLowerPanel.setBackgroundImg(createBackgroundImg(rightLowerPanel
                 .getPreferredSize()));
  
           JTextArea ruTextArea1 = new JTextArea(textArea.getDocument());
           ruTextArea1.setWrapStyleWord(true);
           ruTextArea1.setLineWrap(true);
           rightUpperPanel.add(new JScrollPane(ruTextArea1), BorderLayout.CENTER);
  
           JPanel rightPanel = new JPanel(new GridLayout(0, 1, 1, 1));
           rightPanel.add(rightUpperPanel);
           rightPanel.add(rightLowerPanel);
           rightPanel.setOpaque(false);
           add(centerPanel, BorderLayout.CENTER);
           add(rightPanel, BorderLayout.EAST);
  
        } catch (MalformedURLException e) {
           e.printStackTrace();
        } catch (IOException e) {
           e.printStackTrace();
        }
     }
  
     private BufferedImage createBackgroundImg(Dimension preferredSize) {
        BufferedImage img = new BufferedImage(preferredSize.width,
              preferredSize.height, BufferedImage.TYPE_INT_ARGB);
        Point2D center = new Point2D.Float(img.getWidth()/2, img.getHeight()/2); 
        float radius = img.getWidth() / 2;
        float[] dist = {0.0f, 1.0f};
        Color centerColor = new Color(100, 100, 50);
        Color outerColor = new Color(25, 25, 0);
        Color[] colors = {centerColor , outerColor };
        RadialGradientPaint paint = new RadialGradientPaint(center, radius, dist, colors);
        Graphics2D g2 = img.createGraphics();
        g2.setPaint(paint);
        g2.fillRect(0, 0, img.getWidth(), img.getHeight());
        g2.dispose();
  
        return img;
     }
  
     private static void createAndShowGui() {
        FrameEg mainPanel = new FrameEg();
  
        JFrame frame = new JFrame("FrameEg");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().add(mainPanel);
        frame.setResizable(false);
        frame.pack();
        frame.setLocationByPlatform(true);
        frame.setVisible(true);
     }
  
     public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
           public void run() {
              createAndShowGui();
           }
        });
     }
  }
  
  @SuppressWarnings("serial")
  class MyPanel extends JPanel {
     private Dimension prefSize;
     private BufferedImage backgroundImg;
  
     public MyPanel(Dimension prefSize) {
        this.prefSize = prefSize;
     }
  
     public void setBackgroundImg(BufferedImage background) {
        this.backgroundImg = background;
     }
  
     @Override
     protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        if (backgroundImg != null) {
           g.drawImage(backgroundImg, 0, 0, this);
        }
     }
  
     @Override
     public Dimension getPreferredSize() {
        return prefSize;
     }
  }
  
  @SuppressWarnings("serial")
  class MyBorder extends AbstractBorder {
     private BufferedImage borderImg;
     private Insets insets;
  
     public MyBorder(BufferedImage borderImg, Insets insets) {
        this.borderImg = borderImg;
        this.insets = insets;
     }
  
     @Override
     public void paintBorder(Component c, Graphics g, int x, int y, int width,
           int height) {
        g.drawImage(borderImg, 0, 0, c);
     }
  
     @Override
     public Insets getBorderInsets(Component c) {
        return insets;
     }
  }
  

  看起来像是这样的：

  

  回复于 2024-04-28T01:05:38+08:00