如何将组件放在CardLayout面板的中心

Question

我有一个框架，有几个面板，他们通过CardLayout更改。 在每个面板内部，我将有不同的组件。为了设计面板的GUI，我使用了GridBagLayout。但问题是我用于这些窗格的任何组件或布局，它们都位于页面顶部。所以基本上CardLayout的面板尺寸是一些少量的框架。我想让子面板大小与主CardLayout大小一样大。

主CardLayout的代码：

public class MainPanel extends JPanel {
    private CardLayout cl = new CardLayout();
    private JPanel panelHolder = new JPanel(cl);

    public MainPanel() {
        NewSession session = new NewSession(this);
        ChooseSource chooseSource = new ChooseSource(this);

        panelHolder.add(session, "1");
        panelHolder.add(chooseSource, "2");

        cl.show(panelHolder, "dan");
        add(panelHolder);
    }
    public void showPanel(String panelIdentifier){
        cl.show(panelHolder, panelIdentifier);
    }
}

子小组：

public class ChooseSource extends JPanel {
    MainPanel ob2;
    JButton btn;
    JLabel label;
    JTextField field;

    public ChooseSource(MainPanel mainPanel){
        this.ob2 = mainPanel;


        btn = new JButton("Browse");
        label = new JLabel("Folder ");
        field = new JTextField();

        btn.addActionListener(new ActionListener(){
            @Override
            public void actionPerformed(ActionEvent e){
                ob2.showPanel("1");

            }
        });


        GridBagLayout layout = new GridBagLayout();
        setLayout(layout);

        GridBagConstraints c = new GridBagConstraints();

        c.fill = GridBagConstraints.HORIZONTAL;
        c.gridx = 0;
        c.gridy = 0;
        c.ipady = 20;
        c.gridheight = 2;
        add(btn, c);

        c.fill = GridBagConstraints.HORIZONTAL;
        c.gridx = 1;
        c.gridy = 0;
        c.ipady = 10;
        c.gridheight = 1;
        c.insets = new Insets(0,10,0,0); 
        add(label, c);

        c.fill = GridBagConstraints.HORIZONTAL;
        c.gridx = 1;
        c.gridy = 1;
        c.ipady = 0;
        c.gridheight = 1;
        c.insets = new Insets(0,10,0,0); 
        add(field, c);
    }
}

左图显示了它是怎么回事，而右图是我想要制作的图像。基本上我想访问面板的所有可用空间。

有什么想法吗？

Answer 1

将MainPanel的布局管理器更改为BorderLayout或GridBagLayout