Android之MediaPlayer播放音乐并实现进度条实例

首先，说明我们是从sd卡里读文件，来播放文件！！

1、效果图：

提前工作，往sd卡里放音乐文件，如图：

2、布局文件main.xml

[html] view plain copy

1. <?xml version="1.0" encoding="utf-8"?>  
2. <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  
3.     android:layout_width="fill_parent"  
4.     android:layout_height="fill_parent"  
5.     android:orientation="vertical" >  
6.     <TextView   
7.         android:layout_width="wrap_content"  
8.         android:layout_height="wrap_content"  
9.         android:text="歌曲名："/>  
10.     <TextView   
11.         android:layout_width="wrap_content"  
12.         android:layout_height="wrap_content"  
13.         android:text="blueflawer.mp3"/>  
14.     <Button   
15.         android:layout_width="wrap_content"  
16.         android:layout_height="wrap_content"  
17.         android:text="播放"  
18.         android:id="@+id/play_pause"/>  
19.     <Button   
20.         android:layout_width="wrap_content"  
21.         android:layout_height="wrap_content"  
22.         android:text="重置"  
23.         android:id="@+id/reset"/>  
24.     <SeekBar   
25.         android:layout_width="fill_parent"  
26.         android:layout_height="wrap_content"  
27.         android:id="@+id/seekbar"/>  
28. </LinearLayout>  

3、activity类

[java] view plain copy

1. package cn.csdn.activity;  
2.   
3. import java.io.File;  
4. import java.io.IOException;  
5. import java.util.Timer;  
6. import java.util.TimerTask;  
7.   
8. import android.app.Activity;  
9. import android.media.MediaPlayer;  
10. import android.os.Bundle;  
11. import android.os.Environment;  
12. import android.view.View;  
13. import android.view.View.OnClickListener;  
14. import android.widget.Button;  
15. import android.widget.SeekBar;  
16. import android.widget.SeekBar.OnSeekBarChangeListener;  
17.   
18. public class MyPlayerActivity extends Activity {  
19.     private Button play_pause, reset;  
20.     private SeekBar seekbar;  
21.     private boolean ifplay = false;  
22.     private MediaPlayer player = null;  
23.     private String musicName = "blueflawer.mp3";  
24.     private boolean iffirst = false;  
25.     private Timer mTimer;    
26.     private TimerTask mTimerTask;   
27.     private boolean isChanging=false;//互斥变量，防止定时器与SeekBar拖动时进度冲突   
28.     public void onCreate(Bundle savedInstanceState) {  
29.         super.onCreate(savedInstanceState);  
30.         setContentView(R.layout.main);  
31.         player = new MediaPlayer();  
32.         findViews();// 各组件  
33.     }  
34.   
35.     private void findViews() {  
36.         play_pause = (Button) findViewById(R.id.play_pause);  
37.         reset = (Button) findViewById(R.id.reset);  
38.         play_pause.setOnClickListener(new MyClick());  
39.         reset.setOnClickListener(new MyClick());  
40.   
41.         seekbar = (SeekBar) findViewById(R.id.seekbar);  
42.         seekbar.setOnSeekBarChangeListener(new MySeekbar());  
43.     }  
44.   
45.     class MyClick implements OnClickListener {  
46.         public void onClick(View v) {  
47.             File file = new File(Environment.getExternalStorageDirectory(),  
48.                     musicName);  
49.             // 判断有没有要播放的文件  
50.             if (file.exists()) {  
51.                 switch (v.getId()) {  
52.                 case R.id.play_pause:  
53.                     if (player != null && !ifplay) {  
54.                         play_pause.setText("暂停");  
55.                         if (!iffirst) {  
56.                             player.reset();  
57.                             try {  
58.                                 player.setDataSource(file.getAbsolutePath());  
59.                                 player.prepare();// 准备  
60.   
61.                             } catch (IllegalArgumentException e) {  
62.                                 e.printStackTrace();  
63.                             } catch (IllegalStateException e) {  
64.                                 e.printStackTrace();  
65.                             } catch (IOException e) {  
66.                                 e.printStackTrace();  
67.                             }  
68.                             seekbar.setMax(player.getDuration());//设置进度条  
69.                             //----------定时器记录播放进度---------//    
70.                             mTimer = new Timer();    
71.                             mTimerTask = new TimerTask() {    
72.                                 @Override    
73.                                 public void run() {     
74.                                     if(isChanging==true) {   
75.                                         return;    
76.                                     }  
77.                                     seekbar.setProgress(player.getCurrentPosition());  
78.                                 }    
79.                             };   
80.                             mTimer.schedule(mTimerTask, 0, 10);   
81.                             iffirst=true;  
82.                         }  
83.                         player.start();// 开始  
84.                         ifplay = true;  
85.                     } else if (ifplay) {  
86.                         play_pause.setText("继续");  
87.                         player.pause();  
88.                         ifplay = false;  
89.                     }  
90.                     break;  
91.                 case R.id.reset:  
92.                     if (ifplay) {  
93.                         player.seekTo(0);  
94.                     } else {  
95.                         player.reset();  
96.                         try {  
97.                             player.setDataSource(file.getAbsolutePath());  
98.                             player.prepare();// 准备  
99.                             player.start();// 开始  
100.                         } catch (IllegalArgumentException e) {  
101.                             e.printStackTrace();  
102.                         } catch (IllegalStateException e) {  
103.                             e.printStackTrace();  
104.                         } catch (IOException e) {  
105.                             e.printStackTrace();  
106.                         }  
107.                     }  
108.                     break;  
109.                 }  
110.             }  
111.         }  
112.     }  
113.     //进度条处理  
114.     class MySeekbar implements OnSeekBarChangeListener {  
115.         public void onProgressChanged(SeekBar seekBar, int progress,  
116.                 boolean fromUser) {  
117.         }  
118.   
119.         public void onStartTrackingTouch(SeekBar seekBar) {  
120.             isChanging=true;    
121.         }  
122.   
123.         public void onStopTrackingTouch(SeekBar seekBar) {  
124.             player.seekTo(seekbar.getProgress());  
125.             isChanging=false;    
126.         }  
127.   
128.     }  
129.     //来电处理  
130.     protected void onDestroy() {  
131.         if(player != null){  
132.             if(player.isPlaying()){  
133.                 player.stop();  
134.             }  
135.             player.release();  
136.         }  
137.         super.onDestroy();  
138.     }  
139.   
140.     protected void onPause() {  
141.         if(player != null){  
142.             if(player.isPlaying()){  
143.                 player.pause();  
144.             }  
145.         }  
146.         super.onPause();  
147.     }  
148.   
149.     protected void onResume() {  
150.         if(player != null){  
151.             if(!player.isPlaying()){  
152.                 player.start();  
153.             }  
154.         }  
155.         super.onResume();  
156.     }  
157.   
158. }