Come modificare l'immagine di sfondo predefinita di jdesktoppane?

Question

Come modificare l'immagine di sfondo jdesktoppane in MDI (interfaccia Documenti multipli) utilizzando java netbeans? Significa che ho aggiunto jdesktoppane a Java MDI, quindi ora voglio cambiare l'immagine di sfondo predefinita di quel jdesktoppane che sto usando in Java MDI. Qualche via facile?

Controllare che il collegamento di snapshot allegato possa essere che farai meglio a capire la mia domanda cosa voglio.

http://i50.tinypic.com/iml1e9.jpg

Answer 1

+1 per MadProgrammers commento.

Basta eseguire l'override JDesktopPanepaintComponent(..) e chiamare drawImage(Image img,int x,int y,ImageObserver io) per disegnare un'immagine.

Non dimenticare di onorare la catena vernice e chiamare super.paintComponent(g) come prima chiamata in override paintComponent(..) metodo

Ecco un esempio:

import java.awt.*; 
import java.awt.event.*; 
import java.awt.image.BufferedImage; 
import java.net.URL; 
import javax.imageio.ImageIO; 
import javax.swing.JDesktopPane; 
import javax.swing.JFrame; 
import javax.swing.JInternalFrame; 
import javax.swing.JMenu; 
import javax.swing.JMenuBar; 
import javax.swing.JMenuItem; 
import javax.swing.SwingUtilities; 

public class JInternalFrameDemo { 

    private JDesktopPane jdpDesktop; 
    private static int openFrameCount = 0; 
    private BufferedImage img; 

    public JInternalFrameDemo() { 
     JFrame frame = new JFrame("JInternalFrame Usage Demo"); 
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 

     try { 
      img = ImageIO.read(new URL("http://images1.wikia.nocookie.net/__cb20120817224359/villains/images/6/6a/Nine-Tailed_Fox_(Naruto).jpg")); 
     } catch (Exception ex) { 
      ex.printStackTrace(); 
     } 

     // A specialized layered pane to be used with JInternalFrames 
     jdpDesktop = new JDesktopPane() { 
      @Override 
      protected void paintComponent(Graphics grphcs) { 
       super.paintComponent(grphcs); 
       grphcs.drawImage(img, 0, 0, null); 
      } 

      @Override 
      public Dimension getPreferredSize() { 
       return new Dimension(img.getWidth(), img.getHeight()); 
      } 
     }; 



     createFrame(); // Create first window 

     frame.setContentPane(jdpDesktop); 

     frame.setJMenuBar(createMenuBar()); 

     // Make dragging faster by setting drag mode to Outline 
     jdpDesktop.putClientProperty("JDesktopPane.dragMode", "outline"); 

     frame.pack(); 
     frame.setVisible(true); 
    } 

    protected JMenuBar createMenuBar() { 
     JMenuBar menuBar = new JMenuBar(); 
     JMenu menu = new JMenu("Frame"); 
     menu.setMnemonic(KeyEvent.VK_N); 
     JMenuItem menuItem = new JMenuItem("New IFrame"); 
     menuItem.setMnemonic(KeyEvent.VK_N); 
     menuItem.addActionListener(new ActionListener() { 
      public void actionPerformed(ActionEvent e) { 
       createFrame(); 
      } 
     }); 
     menu.add(menuItem); 
     menuBar.add(menu); 
     return menuBar; 
    } 

    protected void createFrame() { 
     MyInternalFrame frame = new MyInternalFrame(); 
     frame.setVisible(true); 
     // Every JInternalFrame must be added to content pane using JDesktopPane 
     jdpDesktop.add(frame); 
     try { 
      frame.setSelected(true); 
     } catch (java.beans.PropertyVetoException e) { 
     } 
    } 

    public static void main(String[] args) { 
     SwingUtilities.invokeLater(new Runnable() { 
      @Override 
      public void run() { 
       new JInternalFrameDemo(); 
      } 
     }); 
    } 

    class MyInternalFrame extends JInternalFrame { 

     static final int xPosition = 30, yPosition = 30; 

     public MyInternalFrame() { 
      super("IFrame #" + (++openFrameCount), true, // resizable 
        true, // closable 
        true, // maximizable 
        true);// iconifiable 
      setSize(300, 300); 
      // Set the window's location. 
      setLocation(xPosition * openFrameCount, yPosition 
        * openFrameCount); 
     } 
    } 
} 

Answer 2

risolvo in un separato funzione per creare un oggetto desktop.

codice, come di seguito

private JDesktopPane intializeDesktop(JDesktopPane mydesktop,String imagePath,int scalx,int scaly) { 

     // A specialized layered pane to be used with JInternalFrames 
     mydesktop = new JDesktopPane() { 
      ImageIcon icon = new ImageIcon(imagePath); 
      Image image = icon.getImage(); 

      Image newimage = image.getScaledInstance(scalx, scaly, Image.SCALE_SMOOTH); 

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

     return mydesktop; 
    }