为何ACTION_MEDIA_BUTTON无法处理事件？

在关于如何进行use hardware playback control keys to control audio playback的培训部分之后,我创建了一个侦听器类：

public class RemoteControlReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context arg0, Intent intent) {
        if (Intent.ACTION_MEDIA_BUTTON.equals(intent.getAction())) {
            KeyEvent event = (KeyEvent)intent.getParcelableExtra(Intent.EXTRA_KEY_EVENT);
            Log.e(TAG, "ACTION_MEDIA_BUTTON"); 

            int keycode = event.getKeyCode();
            switch (keycode)
            {
                case KeyEvent.KEYCODE_MEDIA_NEXT:
                    Log.e(TAG, "KEYCODE_MEDIA_NEXT"); 
                    break;
                case KeyEvent.KEYCODE_MEDIA_PLAY_PAUSE:
                    Log.e(TAG, "KEYCODE_MEDIA_PLAY_PAUSE"); 
                    break;
                case KeyEvent.KEYCODE_MEDIA_PREVIOUS:
                    Log.e(TAG, "KEYCODE_MEDIA_PREVIOUS"); 
                    break;
                default:
            }

            if (/*KeyEvent.KEYCODE_MEDIA_PLAY*/ 126 == event.getKeyCode()) { // KEYCODE_MEDIA_PLAY undefined for API < 11
                Log.e(TAG, "KEYCODE_MEDIA_PLAY"); 
            }           
        }
    }
}

在活动的onCreate()中注册了它：

private AudioManager mAudioManager;
private ComponentName mRemoteControlReceiver;
...
...
mAudioManager = (AudioManager)getSystemService(Context.AUDIO_SERVICE);
mRemoteControlReceiver = new ComponentName(this, RemoteControlReceiver.class);
mAudioManager.registerMediaButtonEventReceiver(mRemoteControlReceiver);

并将其注册在清单中：

<receiver android:name=".RemoteControlReceiver">
    <intent-filter>
        <action android:name="android.intent.action.MEDIA_BUTTON" />
    </intent-filter>
</receiver>

但是,按下这些按钮中的任何一个都不会导致LogCat上出现任何日志消息！ (无论是否在播放我的媒体时被按下)

我的代码似乎拦截了来自其他媒体播放器的这些事件,但是为什么我看不到任何Log.e()消息？我想念什么？

顺便说一句,当我按下这些按钮中的任何一个时,将显示以下消息：

W/KeyCharacterMap(19801): Can't open keycharmap file
W/KeyCharacterMap(19801): Error loading keycharmap file '/system/usr/keychars/h2w_headset.kcm.bin'. hw.keyboards.131075.devname='h2w headset'
W/KeyCharacterMap(19801): Using default keymap: /system/usr/keychars/qwerty.kcm.bin

解决方法:

您碰巧使用Library Project来实现吗？

如果是这样,您将< receiver>在？库的还是应用程序的？

如果您放入图书馆的图书馆,它将无法使用.您必须将其放置在应用程序的清单中：

<receiver android:name=".RemoteControlReceiver">
    <intent-filter>
        <action android:name="android.intent.action.MEDIA_BUTTON" />
    </intent-filter>
</receiver>

标签：android-audiomanager,android,broadcastreceiver
来源： https://codeday.me/bug/20191013/1909031.html