另一個JPanel中的JPanel

Question

我正在創建帶有JPanel非常簡單的JFrame 。 Panel（ CrosswordPanel ）被實現為另一個類，我嘗試將其添加到框架內的面板（ CrosswordUITest ）中。 執行JButton1之后，面板應該是可見的，但不是。

這是代碼示例：

public class CrosswordUItest extends javax.swing.JFrame  implements EntryListener, ListSelectionListener{

    public CrosswordUItest() {
        initComponents();
    }

    private void initComponents() {

    ...


        jButton1.setFocusable(false);
        jButton1.setHorizontalTextPosition(javax.swing.SwingConstants.CENTER);
        jButton1.setLabel("Generate");
        jButton1.setVerticalTextPosition(javax.swing.SwingConstants.BOTTOM);
        jButton1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton1ActionPerformed(evt);
            }

...


 javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
        jPanel1.setLayout(jPanel1Layout);
        jPanel1Layout.setHorizontalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 0, Short.MAX_VALUE)
        );
        jPanel1Layout.setVerticalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 304, Short.MAX_VALUE)
        );

    panels = new LinkedList<CrosswordPanel>();
        scrollers = new LinkedList<JScrollPane>();

javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(layout.createSequentialGroup()
                        .addComponent(jToolBar1, javax.swing.GroupLayout.PREFERRED_SIZE, 119, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                        .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                            .addComponent(jToolBar2, javax.swing.GroupLayout.PREFERRED_SIZE, 360, javax.swing.GroupLayout.PREFERRED_SIZE)
                            .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING, false)
                                .addGroup(layout.createSequentialGroup()
                                    .addComponent(jButton6)
                                    .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                                    .addComponent(jTextField1))
                                .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 356, javax.swing.GroupLayout.PREFERRED_SIZE))
                            .addComponent(jButton7))
                        .addGap(0, 55, Short.MAX_VALUE))
                    .addGroup(layout.createSequentialGroup()
                        .addComponent(jScrollPane2, javax.swing.GroupLayout.PREFERRED_SIZE, 70, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                        .addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)))
                .addGap(12, 12, 12))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(layout.createSequentialGroup()
                        .addComponent(jToolBar2, javax.swing.GroupLayout.PREFERRED_SIZE, 28, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                            .addComponent(jButton6, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.PREFERRED_SIZE, 26, javax.swing.GroupLayout.PREFERRED_SIZE)
                            .addComponent(jTextField1, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(jButton7, javax.swing.GroupLayout.PREFERRED_SIZE, 26, javax.swing.GroupLayout.PREFERRED_SIZE))
                    .addComponent(jToolBar1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(jScrollPane2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addContainerGap())
        );

        pack();
    }


private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_jButton1ActionPerformed

        Crossword cw = null;
        cw = browser.generate((Integer)  jSpinner1.getValue(), (Integer)  jSpinner2.getValue(), cwDB);
        openCrossword(cw, "");

    }
 void openCrossword(Crossword cw, String id)
    {
        CrosswordPanel panel = new CrosswordPanel();
        panel.setEntryListener(this);
        panels.add(panel);

        JScrollPane scroller = new JScrollPane(panel);
        scroller.setBorder(null);
        scroller.getVerticalScrollBar().setUnitIncrement(20);
        scroller.getHorizontalScrollBar().setUnitIncrement(20);
        add(scroller, BorderLayout.CENTER);
        scrollers.add(scroller);


        panel.setCrossword(cw);
        setCurrentPanel(panel);

        revalidate();
    }

  public void setCurrentPanel(CrosswordPanel p)
    {
        if(p == null)
        {
            return;
        }

        for(int i = 0; i < panels.size(); i++)
        {   
            scrollers.get(i).setVisible(false);
            panels.get(i).setVisible(false);

            if(p == panels.get(i))
            {
                scrollers.get(i).setVisible(true);
                panels.get(i).setVisible(true);     
                jPanel1.add(panels.get(i), BorderLayout.CENTER);        

        }

class CrosswordPanel extends JPanel implements MouseListener, KeyListener
{

...

public CrosswordPanel()
    {
        ...
        setRequestFocusEnabled(true);
        setFocusable(true);
        addMouseListener(this);
        addKeyListener(this);
    }

public void paintComponent(Graphics g)
    {
        ...
    }

在JButton執行動作后，如何將JPanel添加到其他JPanel？ 謝謝你的幫助！

Answer 1

在按下button時將panel2添加到panel1 ：

JPanel panel1, panel2;
JButton button;

//Initialize

button.addActionListener(new ActionListener() {
    @Override
    public void actionPerformed(ActionEvent e) {
        panel1.add(panel2);
    }
});

Answer 2

用於將組件添加（或刪除）到可見GUI的基本代碼是：

panel.add(...);
panel.revalidate(); // to invoke the layout manager
panel.repaint();  // to repaint components with new size/location