事件监听

事件监听

public class TestActionEvent {
    public static void main(String args[]) {
	Frame f = new Frame("Test");
	Button b = new Button("Press Me!");
	Monitor bh = new Monitor();
	b.addActionListener(bh);
	f.add(b,BorderLayout.CENTER);
	f.pack();
	f.setVisible(true);
    }
}

class Monitor implements ActionListener {
    public void actionPerformed(ActionEvent e) {
        System.out.println("a button has been pressed");    
    }
}

 事件源 对象：button

  事件：ActionEvent e

  注册：b.addActionListener(bh);