addActionListener(this)

addActionListener(this)

看书的时候看到这行代码，觉得很奇怪

不是一般写成

1. button.addActionListener(new ActionListener() {
2. public void actionPerformed(ActionEvent e) {
3. ...
4. name.setText(selectedName);
5. }
6. });

要一个ActionListener对象，结果一看

1. public class YourClass implements ActionListener {
2. ... // Other code for your class
3. public void actionPerformed(ActionEvent actionEvent) {
4. System.out.println('I was selected.');
5. }
6. // Code within some method
7. JButton button = new JButton(...);
8. button.addActionListener(this);
9. // More code within some method
10. }

 自己的类都实现了ActionListener，当然就可以addActionListener(this)

不过在YourClass里面如果有很多Button的话，你就得在actionPerformed方法里实现区分它们的方法。