Ich habe ein Panel mit zwei Tasten. Ich versuche, ein Bild in das Bedienfeld einzufügen und möchte nach dem Klicken auf eine Schaltfläche Linien in das Bild zeichnen. Ich habe den folgenden Code verwendet, aber dies scheint nicht zu funktionieren.

public class Try_Panel extends JFrame {
  // start attributes
  private JPanel jPanel1 = new JPanel(null, true);
  private JButton jButton1 = new JButton();
  private JButton jButton2 = new JButton();
  // end attributes

  public Try_Panel(String title) {
    // Frame-Init
    super(title);
    setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
    int frameWidth = 300; 
    int frameHeight = 300;
    setSize(frameWidth, frameHeight);
    Dimension d = Toolkit.getDefaultToolkit().getScreenSize();
    int x = (d.width - getSize().width) / 2;
    int y = (d.height - getSize().height) / 2;
    setLocation(x, y);
    setResizable(false);
    Container cp = getContentPane();
    cp.setLayout(null);
    // start components

    jPanel1.setBounds(48, 24, 209, 145);
    jPanel1.setOpaque(false);
    cp.add(jPanel1);
    jButton1.setBounds(88, 208, 75, 25);
    jButton1.setText("jButton1");
    jButton1.setMargin(new Insets(2, 2, 2, 2));
    jButton1.addActionListener(new ActionListener() { 
      public void actionPerformed(ActionEvent evt) { 
        jButton1_ActionPerformed(evt);
      }
    });
    cp.add(jButton1);
    jButton2.setBounds(184, 208, 75, 25);
    jButton2.setText("jButton2");
    jButton2.setMargin(new Insets(2, 2, 2, 2));
    jButton2.addActionListener(new ActionListener() { 
      public void actionPerformed(ActionEvent evt) { 
        jButton2_ActionPerformed(evt);
      }
    });
    cp.add(jButton2);
    // end components

    setVisible(true);
  } // end of public Try_Panel

  // start methods
  public void jButton1_ActionPerformed(ActionEvent evt) {
      BufferedImage image=new BufferedImage(jPanel1.getWidth(), jPanel1.getHeight(), BufferedImage.TYPE_3BYTE_BGR);
        JLabel l=new JLabel(new ImageIcon(image));
        Graphics graphics = image.getGraphics();
        Graphics2D g = (Graphics2D) graphics;
        g.fillRect(0, 0, image.getWidth(), image.getHeight());
        g.setColor(Color.BLUE);
        g.drawLine(0, 0, 300, 400);
        jPanel1.add(l);
  } // end of jButton1_ActionPerformed

  public void jButton2_ActionPerformed(ActionEvent evt) {
    // TODO add your code here
  } // end of jButton2_ActionPerformed

  // end methods

  public static void main(String[] args) {
    new Try_Panel("Try_Panel");
  } // end of main

} // end of class Try_Panel

Das größte Problem ist, dass derselbe Code in meiner anderen Klasse funktioniert hat.