在Android上使用MediaPlayer的音量问题

Question

I'm having problems playing sounds with MediaPlayer. If the sound starts when the volume of the device is 0, then it won't play. I'll explain: if in the moment of start playing a sound, the device has volume = 0, and afterwards I increase the volume, it still doesn't sound. However, if it has volume != 0 when the sound starts, I can lower it to mute, and then increase it again and it's still playing.

Here is the code:

mpMusic = MediaPlayer.create(context, R.raw.musicmenu_overcast);
float streamVolume = manager.getStreamVolume(AudioManager.STREAM_MUSIC);
streamVolume = streamVolume / manager.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
mpMusic.setVolume(streamVolume, streamVolume);
mpMusic.start();
mpMusic.setLooping(true);

What am I doing wrong? Thank you all!

Answer 1

Note that here, there are 2 kinds of sound level :

• The STREAM volume
• The PLAYER volume

If you set the PLAYER volume to "0", whatever the value of the STREAM volume is, you will never hear anything... If you set the PLAYER volume to "10" for example, you will hear your music with a level that is 10% of the STREAM volume.

In your case, you are setting the volume player to "0" when the STREAM volume is 0... that is why you don't hear anything.

Are you sure that you need to adjust the volume of the PLAYER ?

Answer 2

mpMusic.setLooping(true);

您正在循环播放声音，这就是为什么声音不断播放的原因。