java - 如何更改 JPanel 中 JButton 的大小，整个 JFrame 的大小为 "spread"

Question

所以我有一个问题，因为我的 JButton 太大了，我需要更改它们的大小，例如小矩形或正方形。现在它们看起来像钢琴键。

这是我的粘贴，你们能帮忙吗？ :)我尝试了 SetSize 或 SetDimension 或所有可用的方法，但没有成功。我还没有在溢出这里找到相关主题。你怎么认为？

package sg;

import java.awt.BorderLayout;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Random;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class SG  extends JFrame {

    JPanel pn1;
    JPanel pn2;
    JPanel pn3;
    JPanel pn4;
    JButton[] buttony = new JButton[12];
    JButton start;

    SG() {

       super();


        setSize(1000, 900);
        setResizable(false);

        pn1 = new JPanel();
        pn2 = new JPanel();

         pn1.setLayout(new GridBagLayout());
         pn2.setLayout(new GridLayout(2,6));

        start = new JButton("Start");
        start.addActionListener(new B1());
        pn1.add(start);


        for (int i = 0; i < 12; i++) {
            buttony[i] = new JButton(Integer.toString(i + 1));
            buttony[i].setSize(10, 10);
            pn2.add(buttony[i]);
        }

        add(pn1,BorderLayout.NORTH);
        add(pn2,BorderLayout.CENTER);

    }

    public static void main(String[] args) {
          SG adam = new SG();
         adam.setVisible(true);
    }
   private class B1 implements ActionListener {

        public void actionPerformed(ActionEvent e) {

            Random s = new Random();
            int a = s.nextInt(5);
            System.out.println(a);
        }

}
   }

Answer 1

将 pn2 添加到另一个 JPanel，然后使用 setContentPane 将该面板设置为 JFrame .

完整代码如下:

import java.awt.BorderLayout;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Random;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class SG extends JFrame {

    JPanel pn1;
    JPanel pn2;
    JPanel pn3;
    JPanel pn4;
    JButton[] buttony = new JButton[12];
    JButton start;

    SG() {

        super();

        setSize(1000, 900);
        setResizable(false);

        pn1 = new JPanel();
        pn2 = new JPanel();
        JPanel contentPane = new JPanel();

        pn1.setLayout(new GridBagLayout());
        pn2.setLayout(new GridLayout(2, 6));

        start = new JButton("Start");
        start.addActionListener(new B1());
        pn1.add(start);

        for (int i = 0; i < 12; i++) {
            buttony[i] = new JButton(Integer.toString(i + 1));
            buttony[i].setSize(10, 10);
            pn2.add(buttony[i]);
        }
        contentPane.add(pn2);
        setContentPane(contentPane);
        add(pn1, BorderLayout.NORTH);
        add(pn2, BorderLayout.CENTER);

    }

    public static void main(String[] args) {
        SG adam = new SG();
        adam.setVisible(true);
    }

    private class B1 implements ActionListener {

        public void actionPerformed(ActionEvent e) {

            Random s = new Random();
            int a = s.nextInt(5);
            System.out.println(a);
        }

    }
}