帶自定義邊框的JFrame沒有顯示控件

Question

我正在嘗試製作自己的自定義邊框，並且通過覆蓋JFrame中的繪製函數來完成此操作。我碰到的問題是，在構造函數之後調用paint，導致它在我的控件上繪製窗口。正因爲如此，我的表只有在我碰巧點擊它在JFrame中的位置時纔會出現。我想知道是否有一種方法可以在我的構造函數之前使繪製函數發生，或者有更好的方法來創建自定義邊框。這裏是我的代碼：

public class GuiMain extends JFrame { 

    int posX=0, posY=0; 

    JTable serverList; 

    public GuiMain() 
    { 
     this.setUndecorated(true); 
     this.setLayout(new GridBagLayout()); 

     serverList = new JTable(Variables.servers, Variables.serversHeader); 
     add(serverList); 

     this.addMouseListener(new MouseAdapter(){ 
      public void mousePressed(MouseEvent e) 
      { 
       posX = e.getX(); 
       posY = e.getY(); 
      } 
     }); 
     this.addMouseMotionListener(new MouseAdapter(){ 
      public void mouseDragged(MouseEvent evt) 
      { 
       if(posY <= 20) { 
        setLocation(evt.getXOnScreen()-posX, evt.getYOnScreen()-posY); 
       } 
      } 
     }); 
    } 

    public void paint(Graphics g) 
    { 
     g.setColor(new Color(100, 100, 100)); 
     g.fillRect(0, 0, Main.width, Main.height); 

     g.setColor(new Color(70, 70, 70)); 
     g.fillRect(0, 0, Main.width, 20); 
    } 
} 

任何幫助表示讚賞！謝謝！

Answer 1

您知道這不是最安全的做法，覆蓋頂級窗口的paint(...)。你想創建什麼類型的「邊界」？你打給super.paint(g);的電話在哪裏？我自己創建了我自己的擴展AbstractBorder類的類，然後在JFrame的contentPane的JPanel上使用該Border。

例如，

import java.awt.*; 
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.setUndecorated(true); 
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     frame.getContentPane().add(mainPanel); 
     frame.setResizable(false); 
     frame.pack(); 
     frame.setLocationRelativeTo(null); 
     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; 
    } 
} 

將目光像這樣：