java - 在 Pane 仍在运行的情况下更改发送到 JOptionPane 的 JPanel 的布局

Question

尝试在 JOptionPane 打开时更改其外观，具体取决于用户单击的单选按钮。我究竟做错了什么？例如，如果我添加一个按钮并将 JLabel 从窗口的一侧移动到另一侧，它就会完美地工作。

import java.awt.BorderLayout;
import java.awt.event.*;
import javax.swing.*;
import static javax.swing.JOptionPane.*;

public class ChangePanel extends JFrame{

private JButton click = new JButton("CLICK ME!");

ChangePanel(){
    add(click, BorderLayout.SOUTH);
    click.addActionListener(new ButtonListen());

    setVisible(true);
    setSize(300,100);
    setDefaultCloseOperation(EXIT_ON_CLOSE);
    setLocationRelativeTo(null);
}

public class ButtonListen implements ActionListener{
    public void actionPerformed(ActionEvent e){

        PopUpPanel pop = new PopUpPanel();
        showConfirmDialog(ChangePanel.this, pop, "Changeable", OK_CANCEL_OPTION);           
    }
}
//Send this as Parameter to the ConfirmDialog
public class PopUpPanel extends JPanel implements ActionListener{
    JRadioButton jewelry = new JRadioButton("Jewelry");
    JRadioButton shares = new JRadioButton("Shares");
    JRadioButton machine = new JRadioButton("Machine");

    PopUpPanel(){

        setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));
        ButtonGroup bg = new ButtonGroup();
        JPanel north = new JPanel();
        bg.add(jewelry);
        jewelry.addActionListener(this);
        bg.add(shares);
        shares.addActionListener(this);
        bg.add(machine);
        machine.addActionListener(this);
        north.add(jewelry);
        north.add(shares);
        north.add(machine);
        add(north); 
    }
    //Listener for RadioButtons
    public void actionPerformed(ActionEvent e){
        JTextField info1Txt = new JTextField(12);
        JTextField info2Txt = new JTextField(12);
        JTextField info3Txt = new JTextField(3);;

        JRadioButton b = (JRadioButton)e.getSource();

        if(b.getText().equals("Jewelry")){
            //Dummy test text
            System.out.println("Jewelry");

            JPanel info1 = new JPanel();
            info1.add(new JLabel("info1:"));
            info1.add(info1Txt);
            add(info1);

            JPanel info2 = new JPanel();
            info2.add(new JLabel("info2:"));
            info2.add(info2Txt);
            add(info2);

            JPanel info3 = new JPanel();
            info3.add(new JLabel("info3:"));
            info3.add(info3Txt);
            add(info3);

            validate();
            repaint();

        }else if(b.getText().equals("Shares")){
            //Dummy test text
            System.out.println("Shares");
        }else
            //Dummy test text
            System.out.println("Machine");
    }   
}
public static void main(String[] args){
    new ChangePanel();
}

}

Answer 1

当您使用 BoxLayout 时，您应该向 PopUpPanel 面板提供尺寸提示，而您尚未提供该提示。

当 BoxLayout 从上到下布置组件时，它会尝试按照组件的首选高度调整每个组件的大小。如果布局的垂直空间与首选高度的总和不匹配，则 BoxLayout 会尝试调整组件大小以填充空间。组件会增大或缩小以填充空间，而 BoxLayout 会遵循每个组件的最小和最大尺寸。

查看官方教程页面讨论:BoxLayout Feature