JRadioButton类
| 方法 | 作用 |
|---|---|
| public JRadioButton(Icon icon) | 建立一个单选按钮，并指定图片 |
| public JRadioButton(Icon icon,boolean selected) | 建立一个单选按钮，并指定图片和其是否选定 |
| public JRadioButton(String text) | 建立一个单选按钮，并指定其文字，默认不选定 |
| public JRadioButton(String text,boolean selected) | 建立一个单选按钮，并指定文字和是否选定 |
| public JRadioButton(String text,Icon icon,boolean selected) | 建立一个单选按钮，并指定图片、文字和其是否选定 |
| public void setSelected(boolean b) | 设置是否选中 |
| public boolean isSelected() | 返回是否被选中 |
| public void setText(String text) | 设置显示文本 |
| public void setIcon(Icon defaultIcon) | 设置图片 |
import javax.swing.*;
import java.awt.*;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
class MyRadio{
private Jframe frame = new Jframe("一");
private Container cont = frame.getContentPane();
private JRadioButton jrb1 = new JRadioButton("1");
private JRadioButton jrb2 = new JRadioButton("2");
private JRadioButton jrb3 = new JRadioButton("3");
private JPanel pan = new JPanel();
public MyRadio(){
pan.setBorder(BorderFactory.createTitledBorder("请选择"));
pan.setLayout(new GridLayout(1,3));
pan.add(this.jrb1);
pan.add(this.jrb2);
pan.add(this.jrb3);
ButtonGroup group = new ButtonGroup();
group.add(this.jrb1);
group.add(this.jrb2);
group.add(this.jrb3);
cont.add(pan);
this.frame.setSize(330,80);
this.frame.setVisible(true);
this.frame.addWindowListener(new WindowAdapter() {
@Override
public void windowClosing(WindowEvent e) {
super.windowClosing(e);
System.exit(1);
}
});
}
}
public class Hello {
public static void main(String[] args) {
new MyRadio();
}
}
ButtonGroup group = new ButtonGroup(); group.add(this.jrb1); group.add(this.jrb2); group.add(this.jrb3);
将按钮添加到同一个组中实现单选功能
JRadioButton事件处理使用ItemListener接口进行事件的监听
| 方法 | 作用 |
|---|---|
| void itemStateChanged(ItemEvent e) | 当用户取消或选定某个选项时调用 |
ItemEvent类
| 方法&常量 | 类型 | 作用 |
|---|---|---|
| public static final int SELECTED | 常量 | 选项被选中 |
| public static final int DESELECTED | 常量 | 选项未被选中 |
| public Object getItem() | 方法 | 返回受事件影响的选项 |
| public int getStateChange() | 方法 | 返回选定状态的类型（已选择或已取消） |
import javax.swing.*;
import java.awt.*;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
class MyRadio implements ItemListener{
private JLabel a = new JLabel("选中");
private JLabel b = new JLabel("未选中");
private Jframe frame = new Jframe("一");
private Container cont = frame.getContentPane();
private JRadioButton jrb1 = new JRadioButton("A",true);
private JRadioButton jrb2 = new JRadioButton("B",true);
private JPanel pan = new JPanel();
public MyRadio(){
ButtonGroup group = new ButtonGroup();
group.add(this.jrb1);
group.add(this.jrb2);
jrb1.addItemListener(this);
jrb2.addItemListener(this);
pan.setLayout(new GridLayout(1,4));
pan.add(this.a);
pan.add(this.jrb1);
pan.add(this.b);
pan.add(this.jrb2);
this.frame.add(pan);
this.frame.setSize(200,100);
this.frame.setVisible(true);
this.frame.addWindowListener(new WindowAdapter() {
@Override
public void windowClosing(WindowEvent e) {
super.windowClosing(e);
System.exit(1);
}
});
}
@Override
public void itemStateChanged(ItemEvent e) {
if(e.getSource()==jrb2){
a.setText("未选中");
b.setText("选中");
}else {
b.setText("未选中");
a.setText("选中");
}
}
}
public class Hello {
public static void main(String[] args) {
new MyRadio();
}
}
