一個簡單的Android音樂播放器

實現功能，播放，暫停，重置，進度條的使用

String文件

1. <?xml version="1.0" encoding="utf-8"?>  
2. <resources>  
3.   
4.     <string name="app_name">MusicPlayer</string>  
5.     <string name="music_name">歌曲：</string>  
6.     <string name="play_text">播放</string>  
7.     <string name="pause_text">暫停</string>  
8.     <string name="continue_text">繼續</string>  
9.     <string name="reset_text">重置</string>  
10.     <string name="stop_text">關閉</string>  
11.     <string name="notfoundfile_text">媒體文件不存在</string>  
12.     <string name="notfoundSdcard_text">SDCard不存在</string>  
13.   
14. </resources>  

布局：

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.   
7.     <TextView  
8.         android:layout_width="fill_parent"  
9.         android:layout_height="wrap_content"  
10.         android:text="@string/music_name" />  
11.   
12.     <EditText  
13.         android:id="@+id/musicEt"  
14.         android:layout_width="fill_parent"  
15.         android:layout_height="wrap_content"  
16.         android:text="a.mp3"  
17.          />  
18.     <SeekBar  
19.         android:id="@+id/seekBar"  
20.         android:layout_width="match_parent"  
21.         android:layout_height="wrap_content"  
22.         android:max="10000"  
23.          />  
24.     <TableLayout  
25.         android:layout_width="fill_parent"  
26.         android:layout_height="wrap_content"  
27.         android:stretchColumns="*" >  
28.   
29.         <TableRow >  
30.   
31.             <Button  
32.                 android:id="@+id/playBtn"  
33.                 android:layout_width="wrap_content"  
34.                 android:layout_height="wrap_content"  
35.                 android:text="@string/play_text" />  
36.   
37.             <Button  
38.                 android:id="@+id/pauseBtn"  
39.                 android:layout_width="wrap_content"  
40.                 android:layout_height="wrap_content"  
41.                 android:text="@string/pause_text" />  
42.   
43.             <Button  
44.                 android:id="@+id/resetBtn"  
45.                 android:layout_width="wrap_content"  
46.                 android:layout_height="wrap_content"  
47.                 android:text="@string/reset_text" />  
48.   
49.             <Button  
50.                 android:id="@+id/stopBtn"  
51.                 android:layout_width="wrap_content"  
52.                 android:layout_height="wrap_content"  
53.                 android:text="@string/stop_text" />  
54.         </TableRow>  
55.     </TableLayout>  
56. </LinearLayout>  

Java源碼：

1. package cn.class3g.musicplayer;  
2.   
3. import java.io.File;  
4. import java.io.IOException;  
5.   
6. import android.app.Activity;  
7.   
8. import android.media.MediaPlayer;  
9. import android.os.Bundle;  
10. import android.os.Environment;  
11. import android.os.Handler;  
12. import android.util.Log;  
13. import android.view.View;  
14. import android.view.View.OnClickListener;  
15. import android.widget.Button;  
16. import android.widget.EditText;  
17. import android.widget.SeekBar;  
18. import android.widget.SeekBar.OnSeekBarChangeListener;  
19. import android.widget.Toast;  
20.   
21. public class MusicPlayerActivity extends Activity implements OnClickListener,  
22.         OnSeekBarChangeListener {  
23.   
24.     private static final String TAG = "MusicPlayerActivity";  
25.     EditText musicEt;  
26.     Button playBtn, pauseBtn, resetBtn, stopBtn;  
27.     Handler handler = null;  
28.     Handler fHandler = null;  
29.     MediaPlayer player = null;  
30.   
31.     SeekBar seekbar = null;  
32.   
33.     public void onCreate(Bundle savedInstanceState) {  
34.         super.onCreate(savedInstanceState);  
35.         setContentView(R.layout.main);  
36.   
37.         player = new MediaPlayer();  
38.   
39.         findViews();  
40.   
41.     }  
42.   
43.     private void findViews() {  
44.         musicEt = (EditText) this.findViewById(R.id.musicEt);  
45.         playBtn = (Button) this.findViewById(R.id.playBtn);  
46.         pauseBtn = (Button) this.findViewById(R.id.pauseBtn);  
47.         resetBtn = (Button) this.findViewById(R.id.resetBtn);  
48.         stopBtn = (Button) this.findViewById(R.id.stopBtn);  
49.         seekbar = (SeekBar) this.findViewById(R.id.seekBar);  
50.         playBtn.setOnClickListener(this);  
51.         pauseBtn.setOnClickListener(this);  
52.         resetBtn.setOnClickListener(this);  
53.         stopBtn.setOnClickListener(this);  
54.         seekbar.setOnSeekBarChangeListener(this);  
55.     }  
56.   
57.     public void onClick(View v) {  
58.         String fileName = musicEt.getText().toString();  
59.   
60.         // 確定sdcard狀態是否為已加載   
61.         if (Environment.getExternalStorageState().equals(  
62.                 Environment.MEDIA_MOUNTED)) {  
63.             File file = new File(Environment.getExternalStorageDirectory(),  
64.                     fileName);  
65.   
66.             // 判斷所播放的媒體文件是否存在   
67.             if (file.exists()) {  
68.   
69.                 try {  
70.                     switch (v.getId()) {  
71.                     case R.id.playBtn:  
72.                         playMusic(file);  
73.                         break;  
74.                     case R.id.pauseBtn:  
75.                         if (player.isPlaying()) {  
76.                             player.pause();  
77.                             pauseBtn.setText(R.string.continue_text);  
78.                         } else {  
79.                             player.start();  
80.                             pauseBtn.setText(R.string.pause_text);  
81.                         }  
82.                         break;  
83.                     case R.id.resetBtn:  
84.                         if (player.isPlaying()) {  
85.                             player.seekTo(0);  
86.                         } else {  
87.                             playMusic(file);  
88.                         }  
89.                         break;  
90.                     case R.id.stopBtn:  
91.                         if (player.isPlaying()) {  
92.                             player.stop();  
93.                         }  
94.                         break;  
95.                     }  
96.                 } catch (Exception e) {  
97.                     Log.e(TAG, e.toString());  
98.                 }  
99.             } else {  
100.                 Toast.makeText(this, R.string.notfoundfile_text,  
101.                         Toast.LENGTH_SHORT).show();  
102.             }  
103.         } else {  
104.             Toast.makeText(this, R.string.notfoundSdcard_text,  
105.                     Toast.LENGTH_SHORT).show();  
106.         }  
107.     }  
108.   
109.     protected void onDestroy() {  
110.         if (player != null) {  
111.             if (player.isPlaying()) {  
112.                 player.stop();  
113.             }  
114.             player.release();  
115.         }  
116.         super.onDestroy();  
117.     }  
118.   
119.     protected void onPause() {  
120.         if (player != null) {  
121.             if (player.isPlaying()) {  
122.                 player.pause();  
123.             }  
124.         }  
125.         super.onPause();  
126.     }  
127.   
128.     protected void onResume() {  
129.         if (player != null) {  
130.             if (!player.isPlaying()) {  
131.                 player.start();  
132.             }  
133.         }  
134.         super.onResume();  
135.     }  
136.   
137.     private void playMusic(File file) throws IllegalArgumentException,  
138.             IllegalStateException, IOException {  
139.         if (player != null) {  
140.             player.reset();  
141.             player.setDataSource(file.getAbsolutePath());  
142.             player.prepare();  
143.             player.start();  
144.   
145.             seekbar.setMax(player.getDuration());  
146.             Log.i(TAG, String.valueOf(player.getDuration()));  
147.   
148.             new Thread(new seekBar()).start();  
149.         }  
150.     }  
151.   
152.     class seekBar implements Runnable {  
153.   
154.         int position = 0;  
155.   
156.         public void run() {  
157.             while (player != null) {  
158.                 position = player.getCurrentPosition();  
159.                 seekbar.setProgress(position);  
160.   
161.                 try {  
162.                     Thread.sleep(100);  
163.                 } catch (InterruptedException e) {  
164.                     Log.e(TAG, e.toString());  
165.                 }  
166.             }  
167.   
168.         }  
169.   
170.     }  
171.   
172.     public void onProgressChanged(SeekBar seekBar, int progress,  
173.             boolean fromUser) {  
174.         if (fromUser)  
175.             player.seekTo(progress);  
176.     }  
177.   
178.     public void onStartTrackingTouch(SeekBar seekBar) {  
179.   
180.     }  
181.   
182.     public void onStopTrackingTouch(SeekBar seekBar) {  
183.   
184.     }  
185. }