ex10_6.java

刘艺编著的java教程的课本习题加例题代码 很有用哦！

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

import javax.swing.*;

public class Ex10_6 extends JApplet {
   AudioClip audio1, audio2, audio3, currentaudio;  
   JButton playaudio, loopaudio, stopaudio;
   JComboBox choice;

   public void init()   {
      Container container = getContentPane();
      container.setLayout( new FlowLayout() );

      String choices[] = { "Hi", "ring", "test" };
      choice = new JComboBox( choices );
      choice.addItemListener( new choiceListener());
      container.add( choice );
     
      ButtonHandler handler = new ButtonHandler();
      playaudio = new JButton( "播放" );
      loopaudio = new JButton( "循环" );
      stopaudio = new JButton( "停止" );
      playaudio.addActionListener( handler );
      loopaudio.addActionListener( handler );
      stopaudio.addActionListener( handler );
      container.add( playaudio );
      container.add( loopaudio );
      container.add( stopaudio );

      // 加载声音文件并设置当前的声音文件
      audio1 = getAudioClip( getDocumentBase(), "hi.au" );
      audio2 = getAudioClip( getDocumentBase(), "ring.wav" );
      audio3 = getAudioClip( getDocumentBase(), "test.mid" );
      currentaudio = audio1;

   }  

   // 结束声音文件的播放
   public void stop(){
      currentaudio.stop();
   }

   // 下拉列表框的事件接受器
   class choiceListener implements ItemListener { 

       // 停止当前声音文件的播放并设置当前声音文件为用户的选择
      public void itemStateChanged( ItemEvent e ) {
           currentaudio.stop();

           switch (choice.getSelectedIndex())  {
               case 0:
                  currentaudio =audio1;
                  break;
               case 1:
                  currentaudio =audio2;
                  break;  
	       case 2:
                  currentaudio =audio3;
                  break;              
           }
      }
   }  

   // 播放、循环和停止按钮事件接受器
   private class ButtonHandler implements ActionListener {

      public void actionPerformed( ActionEvent e )  {
         if ( e.getSource() == playaudio ) 
            currentaudio.play();

         else if ( e.getSource() == loopaudio ) 
            currentaudio.loop();

         else if ( e.getSource() == stopaudio ) 
            currentaudio.stop();
      }
   }

}