android.media.AudioManager#getDevices ( )源码实例Demo

/**
 * Determines if the wear device has a built-in speaker and if it is supported. Speaker, even if
 * physically present, is only supported in Android M+ on a wear device..
 */
public final boolean speakerIsSupported() {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        PackageManager packageManager = getPackageManager();
        // The results from AudioManager.getDevices can't be trusted unless the device
        // advertises FEATURE_AUDIO_OUTPUT.
        if (!packageManager.hasSystemFeature(PackageManager.FEATURE_AUDIO_OUTPUT)) {
            return false;
        }
        AudioManager audioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
        AudioDeviceInfo[] devices = audioManager.getDevices(AudioManager.GET_DEVICES_OUTPUTS);
        for (AudioDeviceInfo device : devices) {
            if (device.getType() == AudioDeviceInfo.TYPE_BUILTIN_SPEAKER) {
                return true;
            }
        }
    }
    return false;
}
 

HeadsetTracker(Context context, HeadsetUSourceData data,
               @NonNull PendingIntent event_positive,
               @NonNull PendingIntent event_negative) {
    super(context, data, event_positive, event_negative);

    boolean plugged_in = false;
    Boolean has_microphone = null;

    AudioManager audioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
    if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.M) {
        AudioDeviceInfo[] audioDevices = audioManager.getDevices(AudioManager.GET_DEVICES_ALL);
        for (AudioDeviceInfo deviceInfo : audioDevices) {
            if (deviceInfo.getType() == AudioDeviceInfo.TYPE_WIRED_HEADPHONES
                    || deviceInfo.getType() == AudioDeviceInfo.TYPE_WIRED_HEADSET) {
                plugged_in = true;
                has_microphone = deviceInfo.isSource();
            }
        }
    } else {
        plugged_in = audioManager.isWiredHeadsetOn();
    }
    Boolean match = determine_match(data, plugged_in, has_microphone);
    newSatisfiedState(match);
}
 

@SuppressLint("MissingPermission")
public synchronized boolean isAudioOutputAvailable() {
    Context context = contextWeakReference.get();
    if(context == null){ return false;}

    AudioManager audioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);

    // If API level 23+ audio manager can iterate over all current devices to see if a supported
    // device is present.
    if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M){
        AudioDeviceInfo[] deviceInfos = audioManager.getDevices(AudioManager.GET_DEVICES_OUTPUTS);
        if(deviceInfos != null) {
            for (AudioDeviceInfo deviceInfo : deviceInfos) {
                if (deviceInfo != null && isSupportedAudioDevice(deviceInfo.getType())) {
                    return true;
                }
            }
        }
        return false;
    }

    //This means the SDK version is < M, and our min is 8 so this API is always available
    return audioManager.isBluetoothA2dpOn();
}
 

private static void logAudioDeviceInfo(String tag, AudioManager audioManager) {
  if (Build.VERSION.SDK_INT < 23) {
    return;
  }
  final AudioDeviceInfo[] devices =
      audioManager.getDevices(AudioManager.GET_DEVICES_ALL);
  if (devices.length == 0) {
    return;
  }
  Logging.d(tag, "Audio Devices: ");
  for (AudioDeviceInfo device : devices) {
    StringBuilder info = new StringBuilder();
    info.append("  ").append(deviceTypeToString(device.getType()));
    info.append(device.isSource() ? "(in): " : "(out): ");
    // An empty array indicates that the device supports arbitrary channel counts.
    if (device.getChannelCounts().length > 0) {
      info.append("channels=").append(Arrays.toString(device.getChannelCounts()));
      info.append(", ");
    }
    if (device.getEncodings().length > 0) {
      // Examples: ENCODING_PCM_16BIT = 2, ENCODING_PCM_FLOAT = 4.
      info.append("encodings=").append(Arrays.toString(device.getEncodings()));
      info.append(", ");
    }
    if (device.getSampleRates().length > 0) {
      info.append("sample rates=").append(Arrays.toString(device.getSampleRates()));
      info.append(", ");
    }
    info.append("id=").append(device.getId());
    Logging.d(tag, info.toString());
  }
}
 

private static void logAudioDeviceInfo(String tag, AudioManager audioManager) {
  if (Build.VERSION.SDK_INT < 23) {
    return;
  }
  final AudioDeviceInfo[] devices = audioManager.getDevices(AudioManager.GET_DEVICES_ALL);
  if (devices.length == 0) {
    return;
  }
  Logging.d(tag, "Audio Devices: ");
  for (AudioDeviceInfo device : devices) {
    StringBuilder info = new StringBuilder();
    info.append("  ").append(deviceTypeToString(device.getType()));
    info.append(device.isSource() ? "(in): " : "(out): ");
    // An empty array indicates that the device supports arbitrary channel counts.
    if (device.getChannelCounts().length > 0) {
      info.append("channels=").append(Arrays.toString(device.getChannelCounts()));
      info.append(", ");
    }
    if (device.getEncodings().length > 0) {
      // Examples: ENCODING_PCM_16BIT = 2, ENCODING_PCM_FLOAT = 4.
      info.append("encodings=").append(Arrays.toString(device.getEncodings()));
      info.append(", ");
    }
    if (device.getSampleRates().length > 0) {
      info.append("sample rates=").append(Arrays.toString(device.getSampleRates()));
      info.append(", ");
    }
    info.append("id=").append(device.getId());
    Logging.d(tag, info.toString());
  }
}
 

private AudioDeviceInfo findAudioDevice(int deviceFlag, int deviceType) {
    AudioManager manager = (AudioManager) this.getSystemService(Context.AUDIO_SERVICE);
    AudioDeviceInfo[] adis = manager.getDevices(deviceFlag);
    for (AudioDeviceInfo adi : adis) {
        if (adi.getType() == deviceType) {
            return adi;
        }
    }
    return null;
}
 

private AudioDeviceInfo findAudioDevice(int deviceFlag, int deviceType) {
    AudioManager manager = (AudioManager) this.getSystemService(Context.AUDIO_SERVICE);
    AudioDeviceInfo[] adis = manager.getDevices(deviceFlag);
    for (AudioDeviceInfo adi : adis) {
        if (adi.getType() == deviceType) {
            return adi;
        }
    }
    return null;
}
 

private AudioDeviceInfo findAudioDevice(int deviceFlag, int deviceType) {
    AudioManager manager = (AudioManager) this.getSystemService(Context.AUDIO_SERVICE);
    AudioDeviceInfo[] adis = manager.getDevices(deviceFlag);
    for (AudioDeviceInfo adi : adis) {
        if (adi.getType() == deviceType) {
            return adi;
        }
    }
    return null;
}
 

private AudioDeviceInfo findAudioDevice(int deviceFlag, int deviceType) {
    AudioManager manager = (AudioManager) this.getSystemService(Context.AUDIO_SERVICE);
    AudioDeviceInfo[] adis = manager.getDevices(deviceFlag);
    for (AudioDeviceInfo adi : adis) {
        if (adi.getType() == deviceType) {
            return adi;
        }
    }
    return null;
}
 

private AudioDeviceInfo findAudioDevice(int deviceFlag, int deviceType) {
    AudioManager manager = (AudioManager) this.getSystemService(Context.AUDIO_SERVICE);
    AudioDeviceInfo[] adis = manager.getDevices(deviceFlag);
    for (AudioDeviceInfo adi : adis) {
        if (adi.getType() == deviceType) {
            return adi;
        }
    }
    return null;
}
 

/** Initializes this HeadphoneStateMonitor to start listening to headphone state changes. */
public void startMonitoring() {
  AudioManager audioManager = (AudioManager) mContext.getSystemService(Context.AUDIO_SERVICE);
  // Initialize the active device count.
  mConnectedAudioDevices.clear();
  AudioDeviceInfo[] devices = audioManager.getDevices(AudioManager.GET_DEVICES_OUTPUTS);
  for (AudioDeviceInfo device : devices) {
    if (isExternalDevice(device)) {
      mConnectedAudioDevices.add(device.getId());
    }
  }
  audioManager.registerAudioDeviceCallback(mAudioDeviceCallback, /* use the main thread */ null);
}
 

/**
 * Whether the device is currently connected to bluetooth or wired headphones for audio output.
 * When called on older devices this use a deprecat methods on audioManager to get the same
 * result.
 */
@SuppressWarnings("deprecation")
public static boolean isHeadphoneOn(Context context) {
  AudioManager audioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
  AudioDeviceInfo[] devices = audioManager.getDevices(AudioManager.GET_DEVICES_OUTPUTS);
  for (AudioDeviceInfo device : devices) {
    if (isExternalDevice(device)) {
      // While there can be more than one external audio device, finding one is enough here.
      return true;
    }
  }
  return false;
}