事件处理

package disici;
import java.awt.Color;
import java.awt.event.*;
import javax.swing.*;
public class aaa implements ActionListener{
         private static final Color Color = null;
		JFrame f;
    	 JPanel p;
    	 JButton b;
    	 JLabel l1;
   
     public aaa() {
    	 f = new JFrame();
    	 p = new JPanel();
    	 b = new  JButton ("change");
    	 l1= new  JLabel() ;
    	 b.addActionListener(this);
    	 f.add(p);
    	 p.add(b);
    	 p.add(l1);
    	 f.setSize(400,300);
    	 f.setVisible(true);
     }
     public void actionPerformed(ActionEvent arg0) {
    	 p.setBackground(Color.pink );
     }
     public static void main(String[]args) {
    	 new aaa();
     }
}