为什么要在框架中添加额外的空间？

Question

所以我将此代码添加到JFrame中，其中包含其他布局管理器和组件。

    private JPanel testing123() {
    JPanel j = new JPanel(new FlowLayout());
    jbtOk = new JButton("OK");
    jbtOk.setMnemonic('K');
    jbtExit = new JButton("Exit");
    jbtExit.setMnemonic('x');

    add(jbtOk);
    add(jbtExit);
    j.add(jbtOk);
    j.add(jbtExit);
    return j;
}

没有这个代码，JFrame看起来很好，但是当我添加它时，它会在这两个按钮下添加大量的空白空间。为什么会这样？

这复制了它：

import java.awt.*;
import java.awt.event.*;

import javax.swing.*;
import javax.swing.border.TitledBorder;

public class Test extends JFrame implements ActionListener, KeyListener {

JButton jbtOk, jbtExit;

JPanel p = new JPanel(new GridLayout(0,1));
JPanel gui = new JPanel(new BorderLayout(2,2));

public Test() {

    super("t");
    //setSize(300,300);
    setVisible(true);
    JPanel test = test();
    JPanel testing = testing();
    JPanel testing123 = testing123();
    p.add(test);
    p.add(testing);
    p.add(testing123);
    this.getContentPane().add(p);
    pack();
}

private JPanel test() {
    this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JPanel labelFields = new JPanel(new BorderLayout(2,2));
    labelFields.setBorder(new TitledBorder("m"));
    p.add(gui);
    p.add(labelFields);
    JPanel labels = new JPanel(new GridLayout(0,1,1,1));
    labels.setBorder(new TitledBorder("a"));
    JPanel fields = new JPanel(new GridLayout(0,1,1,1));
    fields.setBorder(new TitledBorder("b"));

    p.add(labels);
    p.add(fields);
    add(fields);
    add(p);
    return gui;
}

private JPanel testing() {
    JPanel guiCenter = new JPanel(new FlowLayout(FlowLayout.CENTER));
    guiCenter.setBorder(new TitledBorder("n"));
    guiCenter.add(new JScrollPane(new JTextArea(5,30)));
    gui.add(guiCenter, BorderLayout.CENTER);
    return guiCenter;
}

private JPanel testing123() {
    JPanel j = new JPanel(new FlowLayout());
    jbtOk = new JButton("OK");
    jbtOk.setMnemonic('K');
    jbtExit = new JButton("Exit");
    jbtExit.setMnemonic('x');

    //add(jbtOk);
    //add(jbtExit);
    j.add(jbtOk);
    j.add(jbtExit);
    return j;
}

@Override
public void actionPerformed(ActionEvent e) {
    // TODO Auto-generated method stub

}

@Override
public void keyPressed(KeyEvent arg0) {
    // TODO Auto-generated method stub

}

@Override
public void keyReleased(KeyEvent arg0) {
    // TODO Auto-generated method stub

}

@Override
public void keyTyped(KeyEvent arg0) {
    // TODO Auto-generated method stub

}
}

Answer 1

  

“我想摆脱OK和Exit按钮下的额外空间。”

问题是您使用GridLayout会使所有JPanel大小相同。您应该做的是将前四个JPanel包裹在GridLayout中，然后保留BorderLayout的默认JFrame，将JPanel添加到{{1} } BorderLayout.CENTER并将JFrame按钮添加到JPanel。这应该可以解决问题

BorderLayout.PAGE_END

完整运行代码

public Test() {

    super("t");
    setDefaultCloseOperation(EXIT_ON_CLOSE);     
    JPanel test = test();
    JPanel testing = testing();
    JPanel testing123 = testing123();
    p.add(test);
    p.add(testing);
    add(p, BorderLayout.CENTER);             <---
    add(testing123, BorderLayout.PAGE_END);  <---
    pack();
    setVisible(true);
}