audio manager . request audio关注Lollipop及更高版本

Question

我目前正在为培训应用程序实现AudioHelper，该应用程序可以在培训期间运行一些激励性演讲。因此，基本上，如果一个演讲正在运行，我想避开我的spotify音频，以便清楚地听到演讲。对于Kitkat和Oreo（及更高版本），我已经解决了这个问题（参见代码）。但对于Lollipop，我找不到正确的实现。在 developer.android.com，他们写道：

对于以Android 5.0（API级别21）及更高版本为目标的应用程序，音频应用程序应使用音频属性来描述您的应用程序正在播放的音频类型。例如，播放语音的应用程序应指定CONTENT_TYPE_SPEECH。源

但是我从哪里开始，我需要什么来达到与kitkat和oreo相同的结果？(AudioFocusRequest。API 21到API 26还没有Builder()。)

这是我的代码片段：

/** Apps running Android 8.0 (API level 26) or greater should use the requestAudioFocus() method,
 * which takes an AudioFocusRequest parameter. The AudioFocusRequest contains information about
 * the audio context and capabilities of your app. The system uses this information to manage
 * the gain and loss of audio focus automatically.
 */
@RequiresApi(Build.VERSION_CODES.O)
private fun loadAndPlayAudioForOreoAndHigher() {
    val audioAttributes = AudioAttributes.Builder()
            .setUsage(AudioAttributes.USAGE_NOTIFICATION)
            .setContentType(AudioAttributes.CONTENT_TYPE_SPEECH)
            .build()

    val audioFocusRequest = AudioFocusRequest.Builder(AudioManager.AUDIOFOCUS_GAIN_TRANSIENT_MAY_DUCK).run {
        setAudioAttributes(audioAttributes)
        setAcceptsDelayedFocusGain(true)
        setOnAudioFocusChangeListener(MediaHelper)
        build()
    }

    val focusRequest = audioManager.requestAudioFocus(audioFocusRequest)
    if(focusRequest == AudioManager.AUDIOFOCUS_REQUEST_GRANTED) {
        mediaPlayer.setOnCompletionListener { audioManager.abandonAudioFocusRequest(audioFocusRequest) }
        mediaPlayer.start()
    }
}

/**
 * For apps that target Android 5.0 (API level 21) and later, audio apps should use
 * AudioAttributes to describe the type of audio your app is playing. For example,
 * apps that play speech should specify CONTENT_TYPE_SPEECH.
 */
@RequiresApi(Build.VERSION_CODES.LOLLIPOP)
private fun loadAndPlayAudioForLollipopAndHigher() {
    // TODO implement audioFocusRequest() and abandonAudioFocusRequest()
}

/**
 * Beginning with Android 2.2 (API level 8), apps manage audio focus by calling
 * requestAudioFocus() and abandonAudioFocus(). Apps must also register an
 * AudioManager.OnAudioFocusChangeListener with both calls in order to receive callbacks
 * and manage their own audio level.
 */
@Suppress("DEPRECATION")
@RequiresApi(Build.VERSION_CODES.KITKAT)
private fun loadAndPlayAudioForKitkatAndHigher() {
    val focusRequestResult = audioManager.requestAudioFocus(this, AudioManager.STREAM_NOTIFICATION, AudioManager.AUDIOFOCUS_GAIN_TRANSIENT_MAY_DUCK)
    if(focusRequestResult == AudioManager.AUDIOFOCUS_REQUEST_GRANTED) {
        mediaPlayer.setOnCompletionListener { audioManager.abandonAudioFocus(this) }
        mediaPlayer.start()
    }
}

Answer 1

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
        videoView.setAudioFocusRequest(AudioManager.AUDIOFOCUS_NONE);
    } else {
        AudioManager audioManager = (AudioManager) getApplicationContext().getSystemService(Context.AUDIO_SERVICE);
        audioManager.requestAudioFocus(null, AudioManager.STREAM_MUSIC, AudioManager.AUDIOFOCUS_GAIN_TRANSIENT_MAY_DUCK);
    }