Android Java实现KEYCODE\u VOLUME\u上下到我的代码

我想知道如何在我的代码上下实现KEYCODE\u VOLUME\u。因此，每当我按下音量向上或向下键时，都会同时反映在我的通知音量控制应用程序上

我想实现的方法如下，当按下物理音量上下按钮时，会使我自己的应用程序音量上下波动：

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
switch (keyCode) {
case KeyEvent.KEYCODE_VOLUME_UP:
    audio.adjustStreamVolume(AudioManager.STREAM_MUSIC,
            AudioManager.ADJUST_RAISE, AudioManager.FLAG_SHOW_UI);
    return true;
case KeyEvent.KEYCODE_VOLUME_DOWN:
    audio.adjustStreamVolume(AudioManager.STREAM_MUSIC,
            AudioManager.ADJUST_LOWER, AudioManager.FLAG_SHOW_UI);
    return true;
default:
    return false;
}
}

我要实现的代码是：

@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    //setContentView(R.layout.activity_main);

    run();
}

public void run()
{
    mgr=(AudioManager)getSystemService(Context.AUDIO_SERVICE);

    final LayoutInflater inflater = 
(LayoutInflater)this.getSystemService(LAYOUT_INFLATER_SERVICE);
    final View ViewLayout = inflater.inflate(R.layout.activity_main, 
(ViewGroup)findViewById(R.id.activity_main));

    alarm=(SeekBar)ViewLayout.findViewById(R.id.alarm);
    music=(SeekBar)ViewLayout.findViewById(R.id.music);
    ring=(SeekBar)ViewLayout.findViewById(R.id.ring);
    system=(SeekBar)ViewLayout.findViewById(R.id.system);
    voice=(SeekBar)ViewLayout.findViewById(R.id.voice);

    alarmVol=(TextView)ViewLayout.findViewById(R.id.alarmVol);
    musicVol=(TextView)ViewLayout.findViewById(R.id.musicVol);
    ringVol=(TextView)ViewLayout.findViewById(R.id.ringVol);
    systemVol=(TextView)ViewLayout.findViewById(R.id.systemVol);
    voiceVol=(TextView)ViewLayout.findViewById(R.id.voiceVol);

    alertDialogBuilder = new AlertDialog.Builder(this);
    //alertDialogBuilder.setIcon(R.mipmap.ic_launcher);
    //alertDialogBuilder.setTitle("Volume Control");
    alertDialogBuilder.setView(ViewLayout);

    initBar(alarm, AudioManager.STREAM_ALARM, alarmVol);
    initBar(music, AudioManager.STREAM_MUSIC, musicVol);
    initBar(ring, AudioManager.STREAM_RING, ringVol);
    initBar(system, AudioManager.STREAM_SYSTEM, systemVol);
    initBar(voice, AudioManager.STREAM_VOICE_CALL, voiceVol);

    alertDialogBuilder.create();
    alertDialogBuilder.show();
}

private void initBar(SeekBar bar, final int stream, final TextView textView) 
{
    final float maxVolume=mgr.getStreamMaxVolume(stream);
    float curVol = mgr.getStreamVolume((stream));
    bar.setMax((int)maxVolume);
    bar.setProgress((int)curVol);
    bar.setKeyProgressIncrement(1);
    textView.setText(String.valueOf((int)(curVol/maxVolume*100)));

    bar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
        public void onProgressChanged(SeekBar bar, int progress,
                                      boolean fromUser) {
            mgr.setStreamVolume(stream, progress, 
AudioManager.FLAG_PLAY_SOUND);

            textView.setText(String.valueOf((int)
((progress/maxVolume)*100)));
        }

        public void onStartTrackingTouch(SeekBar bar) {
        }

        public void onStopTrackingTouch(SeekBar bar) {
        }
    });
}
}

---

请不要自己处理音量键-通常会破坏音量键的行为。在onCreate（）中调用此API:setVolumeControlStream（AudioManager.STREAM_MUSIC）；这告诉AudioManager，当您的应用程序具有焦点时，音量键应调整音乐音量。请不要自己处理音量键-通常会破坏音量键的行为。在onCreate（）中调用此API:setVolumeControlStream（AudioManager.STREAM_MUSIC）；这告诉AudioManager，当您的应用程序具有焦点时，音量键应调整音乐音量。