twolisteninner.java

清华大学第二版

import java.awt.*;
import java.awt.event.*;

public class TwoListenInner{
	private Frame f;
	private TextField tf;

	public static void main(String ars[]){
		TwoListenInner that = new TwoListenInner();
		that.go();
	}
public void go(){
	f = new Frame("Two listeners example");
	f.add("North", new Label("Click and drag the mouse"));
	tf = new TextField(30);
	f.add("South", tf);
	
	f.addMouseMotionListener(new MouseMotionAdapter(){
	public void mouseDragged(MouseEvent e){
		String s = "Mouse dragging: X=" +e.getX() +"Y="+ e.getY();
		tf.setText(s);
		}
	});   // <- 注意括号在这里的用法
	
	f.addMouseListener(new MouseEventHandler());
	f.setSize(300, 200);
	f.setVisible(true);
}

	// MouseMotionHandler 为一个内部类
	public class MouseMotionHandler extends MouseMotionAdapter{
		public void mouseDragged (MouseEvent e){
			String s="Mouse dragging: X="+e.getX() +"Y="+e.getY();
			tf.setText(s);
		}
	}
	// MouseEventHandler
	public class MouseEventHandler extends MouseAdapter{
		public void mouseEntered(MouseEvent e){
			String s = "The mouse entered";
			tf.setText(s);
		}
		public void mouseExited (MouseEvent e){
			String s = "The mouse has left the building";
			tf.setText(s);
		}
	}}