Java Android MediaPlayer 音量很低（已调整音量）
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Android MediaPlayer volume is very low ( already adjusted Volume )
提问by Sammy
I m using the MediaPlayer to play one of the internal alarm ringtone. i m using the setVolume(1.0f, 1.0f) to maximize the volume when the ringtone is played. but the ringtone doesn't play full volume ( when I compare it to playing the ringtone separately or through the built it android alarm)
我正在使用 MediaPlayer 播放内部闹钟铃声之一。我在播放铃声时使用 setVolume(1.0f, 1.0f) 来最大化音量。但铃声没有播放全音量（当我将它与单独播放铃声或通过内置的 android 闹钟进行比较时）
here is my code
这是我的代码
mediaPlayer.setDataSource(context, ringtoneUri);
mediaPlayer.setLooping(looping);
mediaPlayer.setVolume(1.0f, 1.0f);
mediaPlayer.prepare();
mediaPlayer.start();
I added the following permission android.permission.MODIFY_AUDIO_SETTINGS ( not sure if this is needed )
我添加了以下权限 android.permission.MODIFY_AUDIO_SETTINGS （不确定是否需要）
Any Idea why the mediaPlayer still won't play the sound at maximum?
知道为什么 mediaPlayer 仍然不会最大程度地播放声音吗？
采纳答案by Sammy
Here is the solution I found.
这是我找到的解决方案。
AudioManager amanager = (AudioManager) this.getSystemService(Context.AUDIO_SERVICE);
int maxVolume = amanager.getStreamMaxVolume(AudioManager.STREAM_ALARM);
amanager.setStreamVolume(AudioManager.STREAM_ALARM, maxVolume, 0);
MediaPlayer mediaPlayer= new MediaPlayer();
mediaPlayer.setAudioStreamType(AudioManager.STREAM_ALARM); // this is important.
mediaPlayer.setDataSource(context, ringtoneUri);
mediaPlayer.setLooping(looping);
mediaPlayer.prepare();
mediaPlayer.start();
回答by shadowmatter
I encountered the same issue, and then noticed this this in the MediaPlayer documentation:
我遇到了同样的问题，然后在MediaPlayer 文档中注意到了这一点：
While in the Prepared state, properties such as audio/sound volume, screenOnWhilePlaying, looping can be adjusted by invoking the corresponding set methods.
在 Prepared 状态下，可以通过调用相应的 set 方法来调整音频/音量、screenOnWhilePlaying、looping 等属性。
Calling setVolumeaftercalling preparefixes this, so that audio is played at max volume. Actually, according to the docs I just quoted, you should call setLoopingafter prepareas well:
呼叫setVolume后呼叫prepare修复了这个问题，以便以最大音量播放音频。实际上，根据我刚才引用的文档，你应该叫setLooping后prepare，以及：
mediaPlayer.setDataSource(context, ringtoneUri);
mediaPlayer.prepare();
mediaPlayer.setLooping(looping);
mediaPlayer.setVolume(1.0f, 1.0f);
mediaPlayer.start();
