13

有什么方法可以收听Android上的音量变化事件，而不仅仅是接管音量按钮？

我发现唯一可以工作的是here，但它只有在音量控制消失后才能工作。

并非所有设备都有音量按钮，我需要在音量变化发生时立即捕捉它们，而不是在音量对话框消失后捕捉它们。

4

4 回答 4

24

更好的是，您可以ContentObserver按如下方式注册 a：

  getApplicationContext().getContentResolver().registerContentObserver(android.provider.Settings.System.CONTENT_URI, true, new ContentObserver(){...} );

您的 ContentObserver 可能如下所示：

public class SettingsContentObserver extends ContentObserver {
    private AudioManager audioManager;

    public SettingsContentObserver(Context context, Handler handler) {
        super(handler);
        audioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
    }

    @Override
    public boolean deliverSelfNotifications() {
        return false;
    }

    @Override
    public void onChange(boolean selfChange) {
        int currentVolume = audioManager.getStreamVolume(AudioManager.STREAM_MUSIC);

        Log.d(TAG, "Volume now " + currentVolume);
    }
}

完成后：

getApplicationContext().getContentResolver().unregisterContentObserver(mContentObserver);

不过需要注意的是 - 如果快速按下大量按钮，有时通知似乎会延迟。

于 2015-05-25T15:27:17.893 回答
4

好的，现在，我要做的是使用 onKeyDown 听音量按钮（并检查 KEYCODE_VOLUME_DOWN、KEYCODE_VOLUME_MUTE、KEYCODE_VOLUME_UP），并使用一个处理程序，我发布了一个新的可运行文件来检查音量级别。

另外，由于某些设备具有音量对话框，因此根据此链接，我在它消失时添加了一个侦听器。

于 2012-07-10T09:44:33.780 回答
2

Use broadcast receiver VOLUME_CHANGED_ACTION then use AudioManager to obtain current volume.

<receiver android:name="VolumeChangeReceiver" >
    <intent-filter>
         <action android:name="android.media.VOLUME_CHANGED_ACTION" />
    </intent-filter>
</receiver>
于 2014-02-13T19:25:34.713 回答
0

You can use : registerMediaButtonEventReceiver (ComponentName eventReceiver) which registers a component to be the sole receiver of MEDIA_BUTTON intents. 

//  in your activity.
MediaButtonReceiver receiver = new MediaButtonReceiver();

// in onCreate put
registerMediaButtonEventReceiver(receiver); 

class MediaButtonReceiver implements BroadcastReceiver {
     void onReceive(Intent intent) {
          KeyEvent ke = (KeyEvent)intent.getExtra(Intent.EXTRA_KEY_EVENT); 
          if (ke .getKeyCode() == KeyEvent.KEYCODE_VOLUME_DOWN) {
            //action when volume goes down
          }
           if (ke .getKeyCode() == KeyEvent.KEYCODE_VOLUME_UP) {
              //action when volume goes up
          }
     } 
}

   //In both onStop and onPause put :
   unregisterMediaButtonEventReceiver(receiver);

what we are doing here is defining a BroadcastReceiver that deals with ACTION_MEDIA_BUTTON. and use EXTRA_KEY_EVENT which is containing the key event that caused the broadcast to get what was pressed and act upon that.

于 2012-07-03T21:57:25.170 回答