17.txt

java2应用开发指南第一版

例程17-1
//AudioAppletDemo.java
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
public class AudioAppletDemo extends Applet implements ActionListener
{
	AudioClip ac;
	//创建功能按钮，用于控制声音操作
	Button btnStart=new Button("开发播放");
	Button btnPause=new Button("暂停播放");
	Button btnContinue=new Button("继续播放");
	public void init()
	{
		//创建AudioClip对象
		ac=getAudioClip(getDocumentBase(),"computer.au");		
		//给功能按钮添加事件监听器
		btnStart.addActionListener(this);
		btnPause.addActionListener(this);
		btnContinue.addActionListener(this);
		//把功能按钮加入到Applet容器中，并显示
		this.add(btnStart);
		this.add(btnPause);
		this.add(btnContinue);
	}
	public void stop()
	{
		//在Applet停止时关闭音乐
		if(ac!=null)
			ac.stop(); 
	}
	public void actionPerformed(ActionEvent e)
	{
		//如果AudioClip对象为空，则直接返回
		if( ac==null ){
			System.out.println("AudioClip object is not created!");
			return;
		}
		//获取用户激活的按钮
		Object cmd= e.getSource();
		if ( cmd == btnStart ){
			ac.play();
			ac.loop();
		}else if( cmd == btnPause ){
			ac.stop();
		}else if( cmd == btnContinue ){
			ac.play();
			ac.loop();
		}
	}
}



例程17-2
//AudioApplicationDemo.java
import sun.audio.*;		// 引 入sun.audio 包
import java.io.*;
import java.awt.event.*;
import java.awt.*;
public class AudioApplicationDemo extends Frame implements ActionListener
{
	AudioStream  as;
	//创建功能按钮，用于控制声音操作
	Button btnStart=new Button("开发播放");
	Button btnPause=new Button("暂停播放");
	Button btnContinue=new Button("继续播放");
	public AudioApplicationDemo()
	{
		try{
			InputStream in = new FileInputStream ("computer.au");
			//打开一个声音文件流作为输入
			as = new AudioStream (in);
		}catch( Exception e){
			e.printStackTrace();
		}		
		//给功能按钮添加事件监听器
		btnStart.addActionListener(this);
		btnPause.addActionListener(this);
		btnContinue.addActionListener(this);
		//把功能按钮加入到Applet容器中，并显示
		this.setLayout(new FlowLayout());
		this.add(btnStart);
		this.add(btnPause);
		this.add(btnContinue);
		//显示框架窗口
		this.pack();
		this.setVisible(true);
	}
	public static void main( String[] args )
	{
		AudioApplicationDemo fame=new AudioApplicationDemo();
		fame.addWindowListener(new WindowAdapter(){
			public void windowClosing(WindowEvent e)
			{
				System.exit(0);
			}
		});
	}
	//处理按钮事件
	public void actionPerformed(ActionEvent e)
	{
		//如果AudioStream对象为空，则直接返回
		if( as==null ){
			System.out.println("AudioStream object is not created!");
			return;
		}
		//获取用户激活的按钮
		Object cmd= e.getSource();
		
		if ( cmd == btnStart ){
			//播放
			AudioPlayer.player.start (as);			
		}else if( cmd == btnPause ){
			//暂停
			AudioPlayer.player.stop(as);
		}else if( cmd == btnContinue ){
			//继续
			AudioPlayer.player.start (as);
		}
	}
}