/**
 * 作者：@author ZhangShaoWen
 * 日期：2013-12-05
 * 功能：
 */
package com.test;

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class Demo1_3 extends JFrame{

	//定義變數
	Mypanel2 mp = null;
	
	public static void main(String[] args) {
		new Demo1_3();
	}
	
	//建構函式
	public Demo1_3(){
		
		mp = new Mypanel2();
		
		this.add(mp);
		this.addKeyListener(mp);//註冊監聽
		
		this.setSize(300,400);
		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		this.setVisible(true);
	}
}

class Mypanel2 extends JPanel implements KeyListener{
	
	int x = 10;
	int y = 10;
	
	//重寫paint方法
	public void paint(Graphics g){
		//必須呼叫父類的構造方法
		super.paint(g);
		g.setColor(Color.blue);
		g.fillOval(x, y, 10, 10);
	}

	//鍵的一個值被輸出
	@Override
	public void keyTyped(KeyEvent e) {
		// TODO Auto-generated method stub
		
	}

	//按鍵的監聽器
	@Override
	public void keyPressed(KeyEvent e) {
		// TODO Auto-generated method stub
		//System.out.println("鍵被按下"+e.getKeyChar());
		if(e.getKeyCode()==KeyEvent.VK_DOWN){//點擊向下的鍵
			y++;
		}else if(e.getKeyCode()==KeyEvent.VK_UP){//點擊向上的鍵
			y--;
		}else if(e.getKeyCode()==KeyEvent.VK_LEFT){//點擊向左的鍵
			x--;
		}else if(e.getKeyCode()==KeyEvent.VK_RIGHT){//點擊向右的鍵
			x++;
		}
		
		//呼叫repaint方法實現重畫的功能
		this.repaint();
	}

	//釋放鍵的監聽器
	@Override
	public void keyReleased(KeyEvent e) {
		// TODO Auto-generated method stub
		
	}
}