Java程序设计语言(一) 示例程序
P164 程序8.5
与书上程序不完全一样，匿名类使用 lambda
使用 jdk1.8.0_311
package tech.bugstar.practice.gui;
import javax.swing.*;
import javax.swing.border.Border;
import java.awt.*;
import java.awt.event.ActionListener;
import java.awt.event.ItemListener;
public class JFrame85 {
public static void main(String[] args) {
JFrame frame = new JFrame("P164 程序8.5");
//窗体左上角居中
frame.setLocationRelativeTo(null);
Container contentPane = frame.getContentPane();
切换按钮复选按钮和单选按钮示例(contentPane);
frame.pack();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
private static void 切换按钮复选按钮和单选按钮示例(Container contentPane) {
JCheckBox checkBox1 = new JCheckBox("复选按钮 1");
JCheckBox checkBox2 = new JCheckBox("复选按钮 2");
JCheckBox checkBox3 = new JCheckBox("复选按钮 3");
JCheckBox checkBox4 = new JCheckBox("复选按钮 4");
JCheckBox checkBox5 = new JCheckBox("复选按钮 5");
JCheckBox checkBox6 = new JCheckBox("复选按钮 6");
JRadioButton radioButton1 = new JRadioButton("单选按钮 1");
JRadioButton radioButton2 = new JRadioButton("单选按钮 2");
JRadioButton radioButton3 = new JRadioButton("单选按钮 3");
JRadioButton radioButton4 = new JRadioButton("单选按钮 4");
JRadioButton radioButton5 = new JRadioButton("单选按钮 5");
JRadioButton radioButton6 = new JRadioButton("单选按钮 6");
JTextArea textArea = new JTextArea();
JPanel p1 = new JPanel();
JPanel p2 = new JPanel();
JPanel p3 = new JPanel();
JPanel p4 = new JPanel();
JPanel p5 = new JPanel();
JPanel pa = new JPanel();
JPanel pb = new JPanel();
p1.add(checkBox1);
p1.add(checkBox2);
p1.add(checkBox3);
Border etchedBorder = BorderFactory.createEtchedBorder();
Border border = BorderFactory.createTitledBorder(etchedBorder, "复选按钮");
p1.setBorder(border);
p2.add(checkBox4);
p2.add(checkBox5);
p2.add(checkBox6);
border = BorderFactory.createTitledBorder(etchedBorder, "复选按钮组");
p2.setBorder(border);
ButtonGroup group1 = new ButtonGroup();
group1.add(checkBox4);
group1.add(checkBox5);
group1.add(checkBox6);
p3.add(radioButton1);
p3.add(radioButton2);
p3.add(radioButton3);
border = BorderFactory.createTitledBorder(etchedBorder, "单选按钮");
p3.setBorder(border);
p4.add(radioButton4);
p4.add(radioButton5);
p4.add(radioButton6);
border = BorderFactory.createTitledBorder(etchedBorder, "单选按钮组");
p4.setBorder(border);
ButtonGroup group2 = new ButtonGroup();
group2.add(radioButton4);
group2.add(radioButton5);
group2.add(radioButton6);
JScrollPane scrollPane = new JScrollPane(textArea);
p5.setLayout(new BorderLayout());
p5.add(scrollPane);
border = BorderFactory.createTitledBorder(etchedBorder, "输出");
p5.setBorder(border);
ItemListener itemListener = e->{
JCheckBox checkBox = (JCheckBox) e.getSource();
if(checkBox == checkBox1) textArea.append("\n" + (checkBox1.isSelected()?"选中":"取消选中") + " 复选按钮 1 ");
else if(checkBox == checkBox2) textArea.append("\n" + (checkBox2.isSelected()?"选中":"取消选中") + " 复选按钮 2 ");
else if(checkBox == checkBox3) textArea.append("\n" + (checkBox3.isSelected()?"选中":"取消选中") + " 复选按钮 3 ");
else if(checkBox == checkBox4) textArea.append("\n" + (checkBox4.isSelected()?"选中":"取消选中") + " 复选按钮 4 ");
else if(checkBox == checkBox5) textArea.append("\n" + (checkBox5.isSelected()?"选中":"取消选中") + " 复选按钮 5 ");
else textArea.append("\n" + (checkBox6.isSelected()?"选中":"取消选中") + " 复选框按钮 6 ");
};
checkBox1.addItemListener(itemListener);
checkBox2.addItemListener(itemListener);
checkBox3.addItemListener(itemListener);
checkBox4.addItemListener(itemListener);
checkBox5.addItemListener(itemListener);
checkBox6.addItemListener(itemListener);
ActionListener actionListener = e->{
JRadioButton radioButton = (JRadioButton) e.getSource();
if(radioButton == radioButton1) textArea.append("\n" + (radioButton1.isSelected()?"选中":"取消选中") + " 单选按钮 1 ");
else if(radioButton == radioButton2) textArea.append("\n" + (radioButton2.isSelected()?"选中":"取消选中") + " 单选按钮 2 ");
else if(radioButton == radioButton3) textArea.append("\n" + (radioButton3.isSelected()?"选中":"取消选中") + " 单选按钮 3 ");
else if(radioButton == radioButton4) textArea.append("\n" + (radioButton4.isSelected()?"选中":"取消选中") + " 单选按钮 4 ");
else if(radioButton == radioButton5) textArea.append("\n" + (radioButton5.isSelected()?"选中":"取消选中") + " 单选按钮 5 ");
else textArea.append("\n" + (radioButton6.isSelected()?"选中":"取消选中")+" 单选按钮 6 ");
};
radioButton1.addActionListener(actionListener);
radioButton2.addActionListener(actionListener);
radioButton3.addActionListener(actionListener);
radioButton4.addActionListener(actionListener);
radioButton5.addActionListener(actionListener);
radioButton6.addActionListener(actionListener);
pa.setLayout(new GridLayout(0,1));
pa.add(p1);
pa.add(p2);
pb.setLayout(new GridLayout(0,1));
pb.add(p3);
pb.add(p4);
contentPane.setLayout(new GridLayout(0,1));
contentPane.add(pa);
contentPane.add(pb);
contentPane.add(p5);
}
}
程序启动界面
选择复选按钮1
全选复选按钮123
先选复选按钮4再选复选按钮5
选择单选按钮1
全选单选按钮123
先选单选按钮6再选单选按钮5
说明
具有两种状态的按钮不仅可以注册 ActionEvent 事件监听程序，还可以注册 ItemEvent 事件监听程序。ItemListener 接口当按钮的状态发生改变时将会调用该类方法。
ItemListener, ActionListener 的区别在该程序中就是 ItemListener 会监听按钮组里面取消选中的操作，而 ActionListener不会。
ActionEvent 和 ItemEvent 都提供了 getSource() 方法，但返回对象是 Object，需要强转才能使用，ItemEvent 还有个 getItem()方法，返回值和用法和 getSource() 一致。
isSelected() 返回 true 或者 false，表名按钮是否选中
JCheckBox 加入按钮组之后只能单选，JRadioButton 如果不加入按钮组也可以多选，但是通常用 JCheckBox 表示可多选的选择项(不加入按钮组)，而用 JRadioButton 表示只能单选的选择项(加入按钮组)，因此 JCheckBox 称为复选按钮，而 JRadioButton 被称为单选按钮
其他说明
//设置边框
Border etchedBorder = BorderFactory.createEtchedBorder();
Border border = BorderFactory.createTitledBorder(etchedBorder, "复选按钮");
jPanel.setBorder(border);
//加入按钮组
ButtonGroup group1 = new ButtonGroup();
group1.add(checkBox4);
group1.add(checkBox5);
group1.add(checkBox6);
//文本框
JTextArea textArea = new JTextArea();
//带滚动条面板
JScrollPane scrollPane = new JScrollPane(textArea);