不调用onAdjustVolume [英] onAdjustVolume not called

问题描述

我正在尝试使用Android 5.0以上版本的MediaSession在服务中获取HARDWARE_HOOK按钮和音量更改按钮.当屏幕关闭/锁定时，这必须特别起作用.问题是，尽管我能够接收HARDWARE_HOOK按钮事件，但未检测到音量变化.onAdjustVolume方法永远不会被调用.

I am trying to get HARDWARE_HOOK button and volume change button in my service using MediaSession for Android 5.0+ . This has to work specially when screen is off/locked. The problem is that though I am able to receive HARDWARE_HOOK button event, the volume change is not detected. the onAdjustVolume method never gets called.

import android.app.Service;
import android.content.Intent;
import android.media.MediaRouter;
import android.media.session.MediaSession;
import android.os.Binder;
import android.os.IBinder;
import android.support.v4.media.VolumeProviderCompat;
import android.support.v4.media.session.MediaSessionCompat;
import android.util.Log;
import android.view.KeyEvent;
import android.widget.Toast;

public class HookButtonService extends Service{

    public static final String SESSION_TAG = "SampleApp";

    private MediaSessionCompat mMediaSession;

    private VolumeProviderCompat myVolumeProvider;

    public class ServiceBinder extends Binder {

        public HookButtonService getService() {
            return HookButtonService.this;
        }
    }

    private Binder mBinder = new ServiceBinder();

    private MediaSessionCompat.Callback mMediaSessionCallback = new MediaSessionCompat.Callback() {

        @Override
        public boolean onMediaButtonEvent(Intent mediaButtonEvent) {
            Log.d("SampleApp","Media button received");
            if(!MyApplication.isActivityVisible()) {
                Intent dialogIntent = new Intent(getApplicationContext(), MainActivity.class);
                dialogIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                startActivity(dialogIntent);
            }
            return true;
        }
    };



    public HookButtonService() {
    }

    public MediaSessionCompat.Token getMediaSessionToken() {
        return mMediaSession.getSessionToken();
    }

    @Override
    public IBinder onBind(Intent intent) {
        return mBinder;
    }

    @Override
    public void onCreate() {
        super.onCreate();

        mMediaSession = new MediaSessionCompat(this, SESSION_TAG);
        mMediaSession.setCallback(mMediaSessionCallback);

        myVolumeProvider = new VolumeProviderCompat(VolumeProviderCompat.VOLUME_CONTROL_RELATIVE, 100, 50) {
            @Override
            public void onAdjustVolume(int direction) {
                Log.d("SampleApp","Volume change received: "+direction);

            }
        };

        mMediaSession.setActive(true);
        mMediaSession.setFlags(MediaSession.FLAG_HANDLES_MEDIA_BUTTONS |
                MediaSession.FLAG_HANDLES_TRANSPORT_CONTROLS);
        mMediaSession.setPlaybackToRemote(myVolumeProvider);

    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        mMediaSession.release();
    }


}

当您使用播放某些音乐/视频时，需要

推荐答案

onAdjustVolume 和 VolumeProviderCompat 与远程显示器配合使用铸件.例如，当您使用设备上的按钮时，该方法将不会触发沉默和遮蔽.令人困惑的类名，听起来不那么普遍...

onAdjustVolume and VolumeProviderCompat are desired to work with remote displays, when you play some music/video using casting. method won't fire when you are using on-device buttons during e.g. silence and screen-off. confusing class name, its not so universal as it sounds...

afaik在2021年初没有可靠的方法来在屏幕关闭时拦截音量按钮的按下，甚至可能检测到...(@ op，如果您找到解决方案请发表)

afaik at the beginning of 2021 there is no reliable way for intercepting volume button presses when screen off, probably even detecting... (@op if you found solution please post)

原因可能是这是预期的功能"之一.用于减少屏幕关闭过程中的电池消耗的Android版本-直接按下按钮可降低音频管理层，从而省略了框架/应用程序，不允许执行一些其他代码(我们要这样做)

The reason is probably that this is one of intended "features" of Android for reducing battery draining during screen off - distributing button presses straight to lower audio-managing layers ommiting framework/apps, not allowing to execute some additional code (which we want to do)

这篇关于不调用onAdjustVolume的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！