setSize 不影响按钮的大小

Question

我有一个示例代码：

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

public class AWT extends JFrame {

    public static void main(String[] args) {
        final JFrame frame = new JFrame();
        frame.setPreferredSize(new Dimension(600, 450));
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setBackground(Color.green.darker());

        Button btn_1 = new Button("Button 1");
        btn_1.setBackground(Color.green.darker());
        btn_1.setSize(40, 100);
        Button btn_2 = new Button("Button 2");
        btn_2.setBackground(Color.green.darker());
        btn_2.setSize(40, 100);
        Button btn_3 = new Button("Button 3");
        btn_3.setBackground(Color.green.darker());
        btn_3.setSize(40, 100);

        JPanel players = new JPanel(new GridLayout(1, 3));
        players.add(btn_1);
        players.add(btn_2);
        players.add(btn_3);
        players.setBackground(Color.green.darker());
        players.setPreferredSize(new Dimension(450, 80));

        JPanel game = new JPanel();
        game.setBorder(BorderFactory.createBevelBorder(BevelBorder.LOWERED));
        game.setBackground(Color.green);
        game.setPreferredSize(new Dimension(600, 370));

        JPanel content = new JPanel();
        content.setLayout(new BorderLayout());
        frame.setContentPane(content);
        content.add(players, BorderLayout.NORTH);
        content.add(game, BorderLayout.SOUTH);
        frame.pack();
 frame.setVisible(true);
    }
}

结果给了我这样一个窗口：

替代文本http://img710.imageshack。 us/img710/1573/21672037.gif

，虽然它应该会产生类似这样的结果：

alt text http://img686.imageshack.us/img686/8948/44650673.gif

为什么它不以这种方式渲染？

Answer 1

GridLayout 忽略按钮的首选大小。替换

JPanel players = new JPanel(new GridLayout(1, 3));

为

JPanel players = new JPanel(); // default FlowLayout

附录：这是一个让布局和默认首选尺寸完成工作的相关示例。通过指定尽可能少的约束，外观可以根据每个平台的外观进行调整。调用 pack() 时的感觉。

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

public class AWT extends JFrame {

    public static void main(String[] args) {
        final JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JPanel players = new JPanel();
        players.add(new GameButton("Button 1"));
        players.add(new GameButton("Button 2"));
        players.add(new GameButton("Button 3"));
        players.setBackground(GameButton.color);

        JPanel game = new JPanel();
        game.setBorder(BorderFactory.createBevelBorder(BevelBorder.LOWERED));
        game.setBackground(Color.green);
        game.setPreferredSize(new Dimension(600, 450));

        JPanel content = new JPanel();
        content.setLayout(new BorderLayout());
        frame.setContentPane(content);
        content.add(players, BorderLayout.NORTH);
        content.add(game, BorderLayout.CENTER);
        frame.pack();
        frame.setVisible(true);
    }

    private static class GameButton extends JButton {

        private static final Color color = Color.green.darker();
        private static final Font font = new Font("SanSerif", Font.BOLD, 20);
        private String name;

        public GameButton(String name) {
            super(name);
            this.setBackground(color);
            this.setFont(font);
        }
    }
}

Answer 2

1. GridLayout直接拉伸添加到其中的组件。我会使用其他布局，或者如果您确实想要 GridLayout，请查看下面的代码。

2. 您还必须在按钮上使用 setPreferredSize！ （见下文）

导入java.awt.*;

导入 javax.swing.*;
导入 javax.swing.border.BevelBorder;

公共类 AWT 扩展 JFrame {

公共静态无效主（字符串[] args）{
最终 JFrame 框架 = new JFrame();
框架.setPreferredSize(新尺寸(600, 450));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
框架.setBackground(Color.green.darker());

按钮 btn_1 = new Button("按钮 1");
btn_1.setBackground(Color.green.darker());
btn_1.setPreferredSize(新维度(40, 100)); 

按钮 btn_2 = new Button("按钮 2");
btn_2.setBackground(Color.green.darker());
btn_2.setPreferredSize(新维度(40, 100)); 

按钮 btn_3 = new Button("按钮 3");
btn_3.setBackground(Color.green.darker());
btn_3.setPreferredSize(新维度(40, 100));    

GridLayout 布局 = new GridLayout(1, 3);
JPanel 玩家 = new JPanel(layout);
JPanel cell1 = new JPanel();
cell1.add(btn_1);
cell1.setBackground(Color.green.darker());
玩家.add(cell1);
JPanel cell2 = new JPanel();
cell2.add(btn_2);
cell2.setBackground(Color.green.darker());
玩家.add(cell2);
JPanel cell3 = new JPanel();
cell3.add(btn_3);
cell3.setBackground(Color.green.darker());
玩家.add(cell3);
players.setBackground(Color.green.darker());
players.setPreferredSize(new Dimension(450, 80));

JPanel 游戏 = new JPanel();
game.setBorder(BorderFactory.createBevelBorder(BevelBorder.LOWERED));
游戏.setBackground(Color.green);
游戏.setPreferredSize(新维度(600, 370));

JPanel 内容 = new JPanel();
content.setLayout(new BorderLayout());
框架.setContentPane(内容);
content.add(玩家，BorderLayout.NORTH);
content.add(游戏，BorderLayout.SOUTH);
框架.pack();
框架.setVisible(true);
}
}