为什么我的JButtons（“搜索按钮”）不会出现在JPanel上？

Question

我正在构建一个清单Gui应用程序，我希望用描述的第一个字母来搜索项目。所以，我需要在JPanel上显示26个小按钮（将是字母表中的字母）。然后使用搜索按钮来对应保存的文件。但是我似乎不能让按钮显示？？？它只是JPanel。我这里只有整个程序的片段。只是突出显示其中的JPanel和JButton。

JPanel searchPanel = new JPanel( );
searchPanel.setPreferredSize(new Dimension(240, 160));
searchPanel.setBorder(BorderFactory.createTitledBorder("Item Search")); 
searchPanel.setBounds(149, 295, 205, 94);
gridConstraints = new GridBagConstraints();
gridConstraints.gridx = 1;
gridConstraints.gridy = 7;
gridConstraints.gridwidth = 3;
gridConstraints.insets = new Insets(10, 0, 10, 0);
gridConstraints.anchor = GridBagConstraints.CENTER;
getContentPane().add(searchPanel, gridConstraints);
layeredPane.setLayer(searchPanel, 2);
layeredPane.add(searchPanel, gridConstraints); 

 
int x = 0, y = 0;
    // Create Button and Position of Search Panel
    for (int i = 0; i < 26; i++)
    {
        JButton[ ] searchBtn = new JButton[26];
        searchBtn[i] = new JButton( );
        searchBtn[i].setText(String.valueOf((char) (65 + i)));
        searchBtn[i].setFont(new Font("Arial", Font.BOLD, 12));
        searchBtn[i].setMargin(new Insets(-10, -10, -10, -10));
        searchBtn[i].setBounds(149, 295, i, i);
        sizeButton(searchBtn[i], new Dimension(37, 27));
        searchBtn[i].setBackground(Color.YELLOW);
        searchBtn[i].setFocusable(false);
        gridConstraints = new GridBagConstraints();
        gridConstraints.gridx = x;
        gridConstraints.gridy = y;
        searchPanel.add(searchBtn[i], gridConstraints);
        //Search Buttons Method
        searchBtn[i].addActionListener(new ActionListener( ) {
            public void actionPerformed(ActionEvent e)
            {
                searchBtnActionPerformed(e);
            }
            });
        x++;
        //6 Buttons Per Row
        if (x % 6 == 0)
        {
            x = 0;
            y++;
        }
        }
         
         getContentPane( ).setLayout(getLayout( ));
 }

Answer 1

所以，我拿了你的代码，纠正了你试图同时添加两个不同容器的事实，它产生了。。。

现在，我很确定这不是你想要的，基于我对你的代码的有限理解（这是代码处于如此状态以至于不值得尝试挽救的时刻之一），但是，你似乎显然不明白如何使用布局管理器。

您应该花时间查看容器内组件的布局

所以，我扔掉了你的代码，只是做了。。。

public class SearchPane extends JPanel {

    public SearchPane() {
        setBorder(BorderFactory.createTitledBorder("Item Search"));
        setLayout(new GridLayout(-1, 6));

        ActionListener listener = new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                String cmd = e.getActionCommand();
                JOptionPane.showMessageDialog(SearchPane.this, "You want to search for [" + cmd + "]", "Search", JOptionPane.PLAIN_MESSAGE);
            }
        };

        for (int index = 0; index < 26; index++) {
            JButton btn = new JButton(Character.toString('A' + index));
            btn.addActionListener(listener);
            add(btn);
        }
    }
}