android开发---9.MediaPlayer实现音乐播放的demo

一.使用MediaPlayer播放音乐的demo
1. 添加权限
因为音乐文件在sdcard中，所以需要添加外置sd卡的访问权限
AndroidManifest.xml

1. <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>

2. demo代码如下

1. package com.example.MediaPlay;
   
2. 
   
3. import java.io.File;
4. import com.example.MediaPlay.R;
   
5. import android.app.Activity;
   
6. import android.view.View;
   
7. import android.widget.Button;
   
8. import android.media.AudioManager;
   
9. import android.media.MediaPlayer;
   
10. import android.media.MediaPlayer.OnCompletionListener;
    
11. import android.media.MediaPlayer.OnPreparedListener;
    
12. import android.os.Bundle;
    
13. 
    
14. public class MediaPlay extends Activity
    
15. {
    
16.     private String TAG = "cong";
    
17.     private Button btn_play, btn_pause, btn_stop;
    
18.     private MediaPlayer mediaPlayer;
    
19.     private String File_Path = "/mnt/sdcard/Music/letitgo.mp3";     //音乐文件的路径
    
20.     @Override
    
21.     public void onCreate(Bundle savedInstanceState)
    
22.     {
    
23.         super.onCreate(savedInstanceState); 
    
24.         setContentView(R.layout.main);
    
25.         btn_play = (Button) findViewById(R.id.btn_play);
    
26.         btn_pause = (Button) findViewById(R.id.btn_pause);
    
27.         btn_stop = (Button) findViewById(R.id.btn_stop);
    
28. 
    
29.         btn_play.setOnClickListener(click);
    
30.         btn_pause.setOnClickListener(click);
    
31.         btn_stop.setOnClickListener(click);
    
32.     }
    
33.     private View.OnClickListener click = new View.OnClickListener() {
    
34.         @Override
    
35.         public void onClick(View v) {
    
36.             switch (v.getId()) {
    
37.             case R.id.btn_play:
    
38.                 play();
    
39.                 break;
    
40.             case R.id.btn_pause:
    
41.                 pause();
    
42.                 break;
    
43.             case R.id.btn_stop:
    
44.                 stop();
    
45.                 break;
    
46.             default:
    
47.                 break;
    
48.             }
    
49.         }
    
50.     };
    
51.     
    
52.     protected void play() {
    
53.         File file = new File(File_Path);    //确认音乐文件的存在
    
54.         if(!file.exists())
    
55.             return ;
    
56.         try {
    
57.             mediaPlayer = new MediaPlayer();
    
58.             mediaPlayer.setDataSource(File_Path);
    
59.             mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
    
60.             mediaPlayer.prepareAsync();       //异步的方式加载音乐文件
    
61.             mediaPlayer.setOnPreparedListener(new OnPreparedListener() {  //异步加载完音乐文件后会回调此
    
62.                 @Override
    
63.                 public void onPrepared(MediaPlayer mp) {
    
64.                     mediaPlayer.start();               //准备好之后才能start
    
65.                     btn_play.setEnabled(false);
    
66.                 }
    
67.             });
    
68.             mediaPlayer.setOnCompletionListener(new OnCompletionListener() { 
    
69.                 @Override
    
70.                 public void onCompletion(MediaPlayer mp) {
    
71.                     btn_play.setEnabled(true);             //播放完成后btn_play可用
    
72.                 }
    
73.             });
    
74.         } catch (Exception e) {
    
75.             e.printStackTrace();
    
76.         }        
    
77.     }
    
78. 
    
79.     protected void pause() {
    
80.         if (mediaPlayer != null && !mediaPlayer.isPlaying()) {
    
81.             mediaPlayer.start();
    
82.             btn_pause.setText("pause");
    
83.             return;
    
84.         }
    
85.         if (mediaPlayer != null && mediaPlayer.isPlaying()) {
    
86.             mediaPlayer.pause();
    
87.             btn_pause.setText("continue");
    
88.         }
    
89.     }
    
90. 
    
91.     protected void stop() {
    
92.         if (mediaPlayer != null && mediaPlayer.isPlaying()) {
    
93.             mediaPlayer.stop();
    
94.             mediaPlayer.release();
    
95.             mediaPlayer = null;
    
96.             btn_play.setEnabled(true);
    
97.         }
    
98.     }
    
99. 
    
100.     @Override
     
101.     protected void onDestroy() {
     
102.         if (mediaPlayer != null && mediaPlayer.isPlaying()) {
     
103.             mediaPlayer.stop();
     
104.             mediaPlayer.release();
     
105.             mediaPlayer = null;
     
106.         }
     
107.         super.onDestroy();
     
108.     }
     
109. }

media.rar  (下载后改名为media.tar.gz解压)