在做voip通話的過程中，會(huì)頻繁使用到免提播放和聽筒接聽的功能涤伐，而如何正確的切換馒胆，和AudioManager的調(diào)度是分不開的缨称，直接上代碼：

//獲取AudioManager服務(wù)
private val audioManager =
    AppUtils.getApplication().getSystemService(Context.AUDIO_SERVICE) as AudioManager

/**
 * 揚(yáng)聲器切換
 * true: 打開
 */
fun setSpeakerPhoneOn(on: Boolean) {
    if (on) {
        //設(shè)置mode 
        audioManager.mode = AudioManager.MODE_IN_COMMUNICATION
        //設(shè)置音量，解決有些機(jī)型切換后沒聲音或者聲音突然變大的問題
        audioManager.setStreamVolume(
            AudioManager.STREAM_VOICE_CALL,
            audioManager.getStreamVolume(AudioManager.STREAM_VOICE_CALL),
            AudioManager.FX_KEY_CLICK
        )
        //揚(yáng)聲器開啟祝迂，此方法調(diào)用之前需要先設(shè)置好mode
        audioManager.isSpeakerphoneOn = true
    } else {
        //5.0以上
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            //設(shè)置mode 
            audioManager.mode = AudioManager.MODE_IN_COMMUNICATION
            //設(shè)置音量睦尽，解決有些機(jī)型切換后沒聲音或者聲音突然變大的問題
            audioManager.setStreamVolume(
                AudioManager.STREAM_VOICE_CALL,
                audioManager.getStreamVolume(AudioManager.STREAM_VOICE_CALL),
                AudioManager.FX_KEY_CLICK
            )
        } else {
            //設(shè)置mode 
            audioManager.mode = AudioManager.MODE_IN_CALL
            audioManager.setStreamVolume(
                AudioManager.STREAM_VOICE_CALL,
                audioManager.getStreamVolume(AudioManager.STREAM_VOICE_CALL),
                AudioManager.FX_KEY_CLICK
            )
        }
        //揚(yáng)聲器關(guān)閉，此方法調(diào)用之前需要先設(shè)置好mode
        audioManager.isSpeakerphoneOn = false
    }
}

/**
 * 麥克風(fēng)開關(guān)
 * RINGER_MODE_SILENT 靜音,且無振動(dòng)
 * RINGER_MODE_VIBRATE 靜音,但有振動(dòng)
 * RINGER_MODE_NORMAL 正常聲音,振動(dòng)開關(guān)由setVibrateSetting決定.
 * true:靜音
 */
fun setVoiceOn(on: Boolean) {
    audioManager.isMicrophoneMute = on
//    ToastUtils.shortBottom(if (on) "麥克風(fēng)已關(guān)閉" else "麥克風(fēng)已啟用")
}

/**
 * 重設(shè)audioManager狀態(tài)
 * 揚(yáng)聲器切換為NORMAL && 打開麥克風(fēng)
 */
fun resetAudioState() {
    //設(shè)置mode 為喇叭播放
    audioManager.mode = AudioManager.MODE_NORMAL
    //設(shè)置音量型雳，解決有些機(jī)型切換后沒聲音或者聲音突然變大的問題
    audioManager.setStreamVolume(
        AudioManager.STREAM_MUSIC,
        audioManager.getStreamVolume(AudioManager.STREAM_MUSIC),
        AudioManager.FX_KEY_CLICK
    )
    audioManager.isSpeakerphoneOn = true

    setVoiceOn(false)
}

方法調(diào)用代碼如上当凡，下面來分析一下使用中要重點(diǎn)注意的元素：
1.audioManager.mode
AudioManager中給出了如下mode種類，正確的選擇mode進(jìn)行配置纠俭，才能提升用戶體驗(yàn)沿量；

/**
     * Invalid audio mode.
     */
    public static final int MODE_INVALID            = AudioSystem.MODE_INVALID;
    /**
     * Current audio mode. Used to apply audio routing to current mode.
     */
    public static final int MODE_CURRENT            = AudioSystem.MODE_CURRENT;
    /**
     * Normal audio mode: not ringing and no call established.
     */
    public static final int MODE_NORMAL             = AudioSystem.MODE_NORMAL;
    /**
     * Ringing audio mode. An incoming is being signaled.
     */
    public static final int MODE_RINGTONE           = AudioSystem.MODE_RINGTONE;
    /**
     * In call audio mode. A telephony call is established.
     */
    public static final int MODE_IN_CALL            = AudioSystem.MODE_IN_CALL;
    /**
     * In communication audio mode. An audio/video chat or VoIP call is established.
     */
    public static final int MODE_IN_COMMUNICATION   = AudioSystem.MODE_IN_COMMUNICATION;

在VOIP場景中，主要就是為了通話服務(wù)柑晒，所以選擇mode的時(shí)候欧瘪，設(shè)置為MODE_IN_COMMUNICATION 就比較合適，如果設(shè)置為MODE_NORMAL 去開啟揚(yáng)聲器匙赞，就可能會(huì)出現(xiàn)和其他音頻播放聲音混雜佛掖，甚至互相干擾嘯叫嚴(yán)重的問題。