用内部类实现事件处理

[java]代码库

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

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

	public InnerClass() {
		f = new Frame("Inner classes example");
		tf = new TextField(30);
	}

	public void launchFrame() {
		Label label = new Label("Click and drag the mouse");
		f.add(label, BorderLayout.NORTH);
		f.add(tf, BorderLayout.SOUTH);
		f.addMouseMotionListener(new MyMouseMotionListener());/* 参数为内部类对象 */
		f.setSize(300, 200);
		f.setVisible(true);
	}

	class MyMouseMotionListener extends MouseMotionAdapter { /* 内部类开始 */
		public void mouseDragged(MouseEvent e) {
			String s = "Mouse dragging: x=" + e.getX() + "Y=" + e.getY();
			tf.setText(s);
		}
	};

	public static void main(String args[]) {
		InnerClass obj = new InnerClass();
		obj.launchFrame();
	}

}