android MediaPlayer not playing mp3 file

问题

I have written the most basic application I can think of to try to play an mp3 file, but it is not working. I don't get any errors, but when the application starts up, the sound is not played.

public class soundtest extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        MediaPlayer mp = new MediaPlayer();
        mp.create(getApplicationContext(), R.raw.norm_iphone_money);
        mp.start();
    }
}

What am I missing? I have "norm_iphone_money.mp3" inside the res/raw folder. The file plays fine in Windows Media Player and iTunes.

I'm using the latest versions of Java SDK and Eclipse for Java. The app is targeted for Android 2.2 and runs fine in the emulator despite no sound.

回答1:

The problem is that the media volume is set to 0 (not the ringer volume). You can set it by:

AudioManager audioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
audioManager.setStreamVolume(AudioManager.STREAM_MUSIC, 20, 0);

Have a a look at the developer page and another question for the explanation of parameters for setStreamVolume(int, int, int).

回答2:

Try replacing these two lines:

MediaPlayer mp = new MediaPlayer();
mp.create(getApplicationContext(), R.raw.norm_iphone_money);

with this one line:

MediaPlayer mp = MediaPlayer.create(this, R.raw.norm_iphone_money);

And see if that works.

回答3:

The problem is with emulator, change the emulator or try to run the application on a real device. This should solve the problem.

回答4:

The static method create(Context, int) from the type MediaPlayer should be accessed in a static way. Try this:

MediaPlayer.create(getApplicationContext(), R.raw.norm_iphone_money).start();

It will play the .mp3 with this line too

mp.create(getApplicationContext(), R.raw.norm_iphone_money).start();

回答5:

I would suggest this :

MediaPlayer mp = new MediaPlayer();
//bla bla bla
mp = MediaPlayer.create(getApplicationContext(), R.raw.norm_iphone_money);

回答6:

Had the same problem after i clicked to start the Media Player, the screen went black and the app stopped.

i just changed

MediaPlayer mp = MediaPLayer.create(this,R.raw.sound); mp.start();

to

MediaPlayer mp = MediaPLayer.create(this,R.raw.sound).start();

I am not really sure what is the difference there, but it solved my problem.

来源：https://stackoverflow.com/questions/4975636/android-mediaplayer-not-playing-mp3-file