将两个JLabel垂直放在彼此中间

Question

我必须创建两个JLabel,并且应该在JFrame中定位在中心和正下方.我正在使用摆动的gridbaglayout,但我无法弄清楚如何做到这一点.

terminalLabel = new JLabel("No reader connected!", SwingConstants.CENTER);  
terminalLabel.setVerticalAlignment(SwingConstants.TOP); 

cardlabel = new JLabel("No card presented", SwingConstants.CENTER); 
cardlabel.setVerticalAlignment(SwingConstants.BOTTOM);

Answer 1

使用BoxLayout.在下面的代码中,Box类是一个便利类,它创建一个使用BoxLayout的JPanel:

import java.awt.*;
import javax.swing.*;

public class BoxExample extends JFrame
{
    public BoxExample()
    {
        Box box = Box.createVerticalBox();
        add( box );

        JLabel above = new JLabel("Above");
        above.setAlignmentX(JLabel.CENTER_ALIGNMENT);
        box.add( above );

        JLabel below = new JLabel("Below");
        below.setAlignmentX(JLabel.CENTER_ALIGNMENT);
        box.add( below );
    }

    public static void main(String[] args)
    {
        BoxExample frame = new BoxExample();
        frame.setDefaultCloseOperation( EXIT_ON_CLOSE );
        frame.pack();
        frame.setLocationRelativeTo( null );
        frame.setVisible(true);
    }
}