问题描述
- MediaPlayer的setDataSource出错
-
我想用service播放音乐
直接上代码:
private static final MediaPlayer mp = new MediaPlayer();
private String songId;
private int op;@Override public IBinder onBind(Intent intent) { // TODO Auto-generated method stub return null; } @Override public void onCreate() { // TODO Auto-generated method stub // mp = new MediaPlayer(); mp.setOnCompletionListener(this); System.out.println("start mediaplayer"); } public void onDestroy() { System.out.println("stop mediaplayer"); if (mp != null) { mp.stop(); mp.release(); } } @Override public void onCompletion(MediaPlayer mp) { // TODO Auto-generated method stub MainActivity.next(); } @Override @Deprecated public void onStart(Intent intent, int startId) { // TODO Auto-generated method stub } public void option() { switch (op) { case 1: mp.stop(); break; case 2: playMusic(); break; default: Toast.makeText(this, "无法找到操作码", Toast.LENGTH_SHORT).show(); break; } } public void playMusic() { System.out.println("start playing music"); if (mp.isPlaying()) { mp.stop(); } Uri uri = Uri.withAppendedPath( MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, songId); System.out.println("uri is wrong"); try { mp.reset(); mp.setDataSource(MusicService.this, uri); // mp.setLooping(true); mp.prepare(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } mp.start(); }
public void OnMp3Change(String songId, int op) {
// TODO Auto-generated method stub
System.out.println("MusicService:" + songId);
this.songId = songId;
this.op = op;
option();
}
最后在playMusic中的mp.setDataSource(MusicService.this, uri)这里报错。
10-14 07:51:23.515: W/System.err(10908): java.lang.NullPointerException
10-14 07:51:23.519: W/System.err(10908): at android.content.ContextWrapper.getContentResolver(ContextWrapper.java:99)
10-14 07:51:23.522: W/System.err(10908): at android.media.MediaPlayer.setDataSource(MediaPlayer.java:876)
10-14 07:51:23.522: W/System.err(10908): at android.media.MediaPlayer.setDataSource(MediaPlayer.java:854)
10-14 07:51:23.522: W/System.err(10908): at com.example.scanmusic.MusicService.playMusic(MusicService.java:85)
10-14 07:51:23.522: W/System.err(10908): at com.example.scanmusic.MusicService.option(MusicService.java:62)
10-14 07:51:23.525: W/System.err(10908): at com.example.scanmusic.MusicService.OnMp3Change(MusicService.java:113)
10-14 07:51:23.525: W/System.err(10908): at com.example.scanmusic.MainActivity.onListItemClick(MainActivity.java:138)
10-14 07:51:23.525: W/System.err(10908): at android.app.ListActivity$2.onItemClick(ListActivity.java:319)
10-14 07:51:23.525: W/System.err(10908): at android.widget.AdapterView.performItemClick(AdapterView.java:301)
10-14 07:51:23.525: W/System.err(10908): at android.widget.AbsListView.performItemClick(AbsListView.java:1100)
10-14 07:51:23.529: W/System.err(10908): at android.widget.AbsListView$PerformClick.run(AbsListView.java:2749)
10-14 07:51:23.529: W/System.err(10908): at android.widget.AbsListView$1.run(AbsListView.java:3430)
10-14 07:51:23.529: W/System.err(10908): at android.os.Handler.handleCallback(Handler.java:725)
10-14 07:51:23.529: W/System.err(10908): at android.os.Handler.dispatchMessage(Handler.java:92)
10-14 07:51:23.529: W/System.err(10908): at android.os.Looper.loop(Looper.java:137)
10-14 07:51:23.529: W/System.err(10908): at android.app.ActivityThread.main(ActivityThread.java:5106)
10-14 07:51:23.532: W/System.err(10908): at java.lang.reflect.Method.invokeNative(Native Method)
10-14 07:51:23.532: W/System.err(10908): at java.lang.reflect.Method.invoke(Method.java:511)
10-14 07:51:23.532: W/System.err(10908): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:821)
10-14 07:51:23.532: W/System.err(10908): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:588)
10-14 07:51:23.532: W/System.err(10908): at dalvik.system.NativeStart.main(Native Method)
解决方案
在设置dataSource前添加
mp.setAudioStreamType(AudioManager.STREAM_MUSIC);
mp.setDataSource(path);
解决方案二:
楼主,你报错那行下面打印的是啥?打印Uri看看路径是否正确。
我记得这个方法获得的路径是SD Card里的,你SD Card里放文件了么?