窗口监听事件

匿名内部类

 

 

public class demo01 {
    public static void main(String[] args) {
        new MyFrame("hahhahhs");
    }
}
class MyFrame extends Frame{
    public MyFrame(String title){
        super(title);
        setBounds(200,200,300,300);
        setVisible(true);
       this.addWindowListener(new WindowAdapter() {
            @Override
            public void windowClosed(WindowEvent e) {
                System.exit(0);
            }
           @Override
           public void windowActivated(WindowEvent e) {
                Frame frame=(Frame) e.getSource();
               frame.setTitle("被激活了");
               System.out.println("被激活了");
            }
        });
    }
}