下面列出了android.media.AudioManager#getStreamVolume ( ) 实例代码，或者点击链接到github查看源代码，也可以在右侧发表评论。
/**
* @param manager AudioManager
* @return True if {@link android.media.AudioManager#STREAM_SYSTEM} exists.
*/
@Override
public boolean apply(AudioManager manager) {
// Remember the volumes that we started at.
final int systemVolume = manager.getStreamVolume(STREAM_SYSTEM);
final int[] streams = new int[] {
STREAM_RING, STREAM_MUSIC, STREAM_ALARM, STREAM_NOTIFICATION
};
for (int stream : streams) {
// Set each stream volume differently, see if system is linked.
final int prevVolume = manager.getStreamVolume(stream);
manager.setStreamVolume(STREAM_SYSTEM, 4, 0);
manager.setStreamVolume(stream, 2, 0);
final int newSystemVolume = manager.getStreamVolume(STREAM_SYSTEM);
final int newVolume = manager.getStreamVolume(stream);
manager.setStreamVolume(stream, prevVolume, 0);
if (newVolume == newSystemVolume) return false;
}
manager.setStreamVolume(STREAM_SYSTEM, systemVolume, 0);
return true;
}
@SuppressLint("NewApi")
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
Logd(TAG, "Starting video service...");
String message = intent.getStringExtra("message");
context = getApplicationContext();
if (message.startsWith("Command:FrontVideo:") || message.startsWith("Command:FrontVideoMAX:"))
cameraInt = 1;
if (message.startsWith("Command:RearVideoMAX:") || message.startsWith("Command:FrontVideoMAX:"))
max = true;
String s = message.replace("Command:FrontVideo:", "").replace("Command:FrontVideoMAX:", "").replace("Command:RearVideo:", "").replace("Command:RearVideoMAX:", "");
seconds = Integer.parseInt(s);
Handler handler = new Handler();
handler.postDelayed(new Runnable() {
@Override
public void run() {
captureImage();
}
}, 2000);
am = (AudioManager) getApplicationContext().getSystemService("audio");
volume = am.getStreamVolume(1);
Logd(TAG, "Current volume: " + volume);
//if (Build.VERSION.SDK_INT < 14)
am.setStreamVolume(1, 0, 0);
return START_STICKY;
}
private void soundAlert(String soundUri) {
manager = (AudioManager) mContext.getSystemService(Context.AUDIO_SERVICE);
int maxVolume = manager.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
currentVolume = manager.getStreamVolume(AudioManager.STREAM_MUSIC);
manager.setStreamVolume(AudioManager.STREAM_MUSIC, maxVolume, 0);
Uri notification = Uri.parse(soundUri);
MediaPlayer player = MediaPlayer.create(mContext, notification);
player.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
@Override
public void onCompletion(MediaPlayer mp) {
manager.setStreamVolume(AudioManager.STREAM_MUSIC, currentVolume, 0);
}
});
player.start();
}
@Override
public void onChange (boolean selfChange)
{
if (MainActivity.mainActivity == null) return;
//
float minVolume = OBConfigManager.sharedManager.getMinimumAudioVolumePercentage() / (float) 100;
// if value is not present in the config, the min volume will be -.01
AudioManager am = (AudioManager) MainActivity.mainActivity.getSystemService(Context.AUDIO_SERVICE);
currentVolume = am.getStreamVolume(AudioManager.STREAM_MUSIC);
int maxVolume = am.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
int minVolumeLimit = Math.round(maxVolume * minVolume);
if (currentVolume < minVolumeLimit)
{
MainActivity.log("Current Volume (" + currentVolume + ") lower than permitted minimum (" + minVolumeLimit + "). Resetting value");
am.setStreamVolume(AudioManager.STREAM_MUSIC, minVolumeLimit, 0);
currentVolume = minVolumeLimit;
}
OBAnalyticsManager.sharedManager.deviceVolumeChanged(currentVolume / (float) maxVolume);
OBSystemsManager.sharedManager.refreshStatus();
}
/**
* 调整音量
*
* @param increase true=增加百分之20 false=减少百分之20
*/
public String ajustVol(boolean increase, int progress) {
AudioManager mAudioManager = (AudioManager) mContext.getSystemService(Context.AUDIO_SERVICE);
int currentVolume = mAudioManager.getStreamVolume(AudioManager.STREAM_MUSIC);
float max = mAudioManager.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
currentVolume = (int) (currentVolume + max * (progress / 100.0f) * (increase ? 1 : -1));
if (currentVolume < 0)
currentVolume = 0;
else if (currentVolume > max)
currentVolume = (int) max;
mAudioManager.setStreamVolume(AudioManager.STREAM_MUSIC, currentVolume, 0);
//弹出系统媒体音量调节框
mAudioManager.adjustStreamVolume(AudioManager.STREAM_MUSIC,
AudioManager.ADJUST_SAME, AudioManager.FLAG_PLAY_SOUND
| AudioManager.FLAG_SHOW_UI);
NumberFormat nf = NumberFormat.getPercentInstance();
//返回数的整数部分所允许的最大位数
nf.setMaximumIntegerDigits(3);
//返回数的小数部分所允许的最大位数
// nf.setMaximumFractionDigits(2);
return nf.format(currentVolume / max);
}
@Override
protected void onStart() {
super.onStart();
mSensorManager.registerListener(this, mAccelerometer, SensorManager.SENSOR_DELAY_UI);
// Set the media volume to max.
setVolumeControlStream(AudioManager.STREAM_MUSIC);
AudioManager audioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
mOriginalVolume = audioManager.getStreamVolume(AudioManager.STREAM_MUSIC);
audioManager.setStreamVolume(
AudioManager.STREAM_MUSIC, audioManager.getStreamMaxVolume(AudioManager.STREAM_MUSIC), 0);
setState(State.DISCOVERING);
}
@Override
public int getVolume() {
// Get the system's audio service and get media volume from it.
AudioManager audioManager = (AudioManager) getContext().getSystemService(Context.AUDIO_SERVICE);
if (audioManager != null) {
double volume = audioManager.getStreamVolume(AudioManager.STREAM_MUSIC);
double max = audioManager.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
if (max <= 0) {
return 0;
}
// Return a range from 0-100.
return (int) ((volume / max) * 100.0f);
}
return 0;
}
@Override
public void onCreate() {
super.onCreate();
Logd(TAG, "Starting ringer.");
context = getApplicationContext();
AudioManager audio = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
currentVolume = audio.getStreamVolume(AudioManager.STREAM_MUSIC);
audio.setStreamVolume(AudioManager.STREAM_MUSIC, audio.getStreamMaxVolume(AudioManager.STREAM_MUSIC), AudioManager.FLAG_REMOVE_SOUND_AND_VIBRATE);
mPlayer = MediaPlayer.create(context, R.raw.ring);
mPlayer.setLooping(true);
mPlayer.start();
}
@Override
public void init(Context context) {
audioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
int maxVolume = audioManager.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
setMaxLevel(maxVolume);
currentLevel = audioManager.getStreamVolume(AudioManager.STREAM_MUSIC);
audioManager.setStreamVolume(AudioManager.STREAM_MUSIC, currentLevel, 0);
setLevel(DEFAULT_VOLUME_LEVEL);
}
@Override
public void onBackPressed() {
//To support reverse transitions when user clicks the device back button
AudioManager am = (AudioManager) getSystemService(AUDIO_SERVICE);
int volume_level= am.getStreamVolume(AudioManager.STREAM_MUSIC);
mediaPlayer.setVolume(volume_level-(volume_level/2),volume_level-(volume_level/2));
supportFinishAfterTransition();
}
public static int getStreamVolume(int streamType) {
if (ClientProperties.getApplicationContext() != null) {
AudioManager am = (AudioManager)ClientProperties.getApplicationContext().getSystemService(Context.AUDIO_SERVICE);
if (am != null)
return am.getStreamVolume(streamType);
else
return -2;
}
return -1;
}
@Override
protected void onDestroy() {
super.onDestroy();
AudioManager am = (AudioManager) getSystemService(AUDIO_SERVICE);
int volume_level= am.getStreamVolume(AudioManager.STREAM_MUSIC);
mediaPlayer.setVolume(volume_level-(volume_level/2),volume_level-(volume_level/2));;
//finish();
mediaPlayer.reset();
}
private void normalizeVolume(Context c, float startVolume) {
final AudioManager audio =
(AudioManager) c.getSystemService(Context.AUDIO_SERVICE);
systemNotificationVolume =
audio.getStreamVolume(AudioManager.STREAM_ALARM);
audio.setStreamVolume(AudioManager.STREAM_ALARM,
audio.getStreamMaxVolume(AudioManager.STREAM_ALARM), 0);
setVolume(startVolume);
}
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
// assume that the user cancels the call if it is ringing
if (keyCode == KeyEvent.KEYCODE_BACK) {
if (!canCallBeResumed()) {
if (null != mCall) {
mCall.hangup("");
}
} else {
saveCallView();
}
} else if ((keyCode == KeyEvent.KEYCODE_VOLUME_DOWN) || (keyCode == KeyEvent.KEYCODE_VOLUME_UP)) {
// this is a trick to reduce the ring volume :
// when the call is ringing, the AudioManager.Mode switch to MODE_IN_COMMUNICATION
// so the volume is the next call one whereas the user expects to reduce the ring volume.
if ((null != mCall) && mCall.getCallState().equals(IMXCall.CALL_STATE_RINGING)) {
AudioManager audioManager = (AudioManager) CallViewActivity.this.getSystemService(Context.AUDIO_SERVICE);
// IMXChrome call issue
if (audioManager.getMode() == AudioManager.MODE_IN_COMMUNICATION) {
int musicVol = audioManager.getStreamVolume(AudioManager.STREAM_VOICE_CALL) * audioManager.getStreamMaxVolume(AudioManager.STREAM_MUSIC) / audioManager.getStreamMaxVolume(AudioManager.STREAM_VOICE_CALL);
audioManager.setStreamVolume(AudioManager.STREAM_MUSIC, musicVol, 0);
}
}
}
return super.onKeyDown(keyCode, event);
}
private void setStreamVolume() {
AudioManager audioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
int volume = audioManager.getStreamVolume(AudioManager.STREAM_MUSIC);
if (volume != 0) {
debug("setStreamVolume:" + volume);
Log.d("ChatActivity","setStreamVolume : " + volume);
MainActivity.volume = volume;
}
}
/**
* Calculates the volume for {@link SpeechControllerImpl#setSpeechVolume(float)} when announcing
* "TalkBack off".
*
* <p>TalkBack switches to use {@link AudioManager#STREAM_ACCESSIBILITY} from Android O. However,
* when announcing "TalkBack off" before turning TalkBack off, the audio goes through {@link
* AudioManager#STREAM_MUSIC}. It's because accessibility stream has already been shut down before
* {@link #onUnbind(Intent)} is called.
*
* <p>To work around this issue, it's not recommended to directly override media stream volume.
* Instead, we can adjust the relative TTS volume to match the original accessibility stream
* volume.
*
* @return TTS volume in [0.0f, 1.0f].
*/
private float calculateFinalAnnouncementVolume() {
if (!FeatureSupport.hasAcessibilityAudioStream(this)) {
return 1.0f;
}
AudioManager audioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
int musicStreamVolume = audioManager.getStreamVolume(AudioManager.STREAM_MUSIC);
int musicStreamMaxVolume = audioManager.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
int accessibilityStreamVolume =
(volumeMonitor == null) ? -1 : volumeMonitor.getCachedAccessibilityStreamVolume();
int accessibilityStreamMaxVolume =
(volumeMonitor == null) ? -1 : volumeMonitor.getCachedAccessibilityMaxVolume();
if (musicStreamVolume <= 0
|| musicStreamMaxVolume <= 0
|| accessibilityStreamVolume < 0
|| accessibilityStreamMaxVolume <= 0) {
// Do not adjust volume if music stream is muted, or when any volume is invalid.
return 1.0f;
}
if (accessibilityStreamVolume == 0) {
return 0.0f;
}
// Depending on devices/API level, a stream might have 7 steps or 15 steps adjustment.
// We need to normalize the values to eliminate this difference.
float musicVolumeFraction = (float) musicStreamVolume / musicStreamMaxVolume;
float accessibilityVolumeFraction =
(float) accessibilityStreamVolume / accessibilityStreamMaxVolume;
if (musicVolumeFraction <= accessibilityVolumeFraction) {
// Do not adjust volume when a11y stream volume is louder than music stream volume.
return 1.0f;
}
// AudioManager measures the volume in dB scale, while TTS measures it in linear scale. We need
// to apply exponential operation to map dB/logarithmic-scaled diff value into linear-scaled
// multiplier value.
// The dB scaling could be different based on devices/OEMs/streams, which is not under our
// control.
// What we can do is to try our best to adjust the volume and avoid sudden volume increase.
// TODO: The parameters in Math.pow() are results from experiments. Feel free to change
// them.
return (float) Math.pow(10.0f, (accessibilityVolumeFraction - musicVolumeFraction) / 0.4f);
}
@Override
public void onReceive(Context context, Intent intent) {
if (intent==null)
return;
if (intent.getAction().equals(Intent.ACTION_POWER_DISCONNECTED)){
//on power disconnect scan for new files
new UpdateAllFiles().execute(new ArrayList<String>());
}
if (intent.getAction().equals("android.media.VOLUME_CHANGED_ACTION")){
AudioManager am = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
if (am == null)
return;
int currVolume = am.getStreamVolume(AudioManager.STREAM_MUSIC);
int maxVolume = am.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
if (currVolume == maxVolume && (System.currentTimeMillis()- startVolumeUpFlag) > 2000) {
if (firstVolumeUpFlag) {
firstVolumeUpFlag = false;
if (isPlaying()) {
startVolumeUpFlag = System.currentTimeMillis();
playNext();
}
}
else {
firstVolumeUpFlag = true;
}
}
else {
startVolumeUpFlag = System.currentTimeMillis();
}
}
if (intent.getAction().equals(Intent.ACTION_HEADSET_PLUG)) {
int state = intent.getIntExtra("state", -1);
switch (state){
case 0:
if (isPlaying()) {
isUnpluggedFlag = true;
pause();
}
break;
case 1:
if (isUnpluggedFlag && isPaused()) {
isUnpluggedFlag = false;
playFromPause();
}
break;
default:
break;
}
}
}
private void initSound() {
am = (AudioManager) getBaseActivity().getSystemService(Context.AUDIO_SERVICE);
currentSound = am.getStreamVolume(AudioManager.STREAM_MUSIC);
}
@Override
public void adjustVolumeLevel(double adjustPercent) {
if (disableGestures) {
return;
}
// We are setting volume percent to a value that should be from -1.0 to 1.0. We need to limit it here for these values first
if (adjustPercent < -1.0f) {
adjustPercent = -1.0f;
} else if (adjustPercent > 1.0f) {
adjustPercent = 1.0f;
}
AudioManager audioManager = (AudioManager) getContext().getSystemService(Context.AUDIO_SERVICE);
final int STREAM = AudioManager.STREAM_MUSIC;
// Max volume will return INDEX of volume not the percent. For example, on my device it is 15
int maxVolume = audioManager.getStreamMaxVolume(STREAM);
if (maxVolume == 0) return;
if (startVolumePercent < 0) {
// We are getting actual volume index (NOT volume but index). It will be >= 0.
int curVolume = audioManager.getStreamVolume(STREAM);
// And counting percents of maximum volume we have now
startVolumePercent = curVolume * 1.0f / maxVolume;
}
// Should be >= 0 and <= 1
double targetPercent = startVolumePercent + adjustPercent;
if (targetPercent > 1.0f) {
targetPercent = 1.0f;
} else if (targetPercent < 0) {
targetPercent = 0;
}
// Calculating index. Test values are 15 * 0.12 = 1 ( because it's int)
int index = (int) (maxVolume * targetPercent);
if (index > maxVolume) {
index = maxVolume;
} else if (index < 0) {
index = 0;
}
audioManager.setStreamVolume(STREAM, index, 0);
indicatorImageView.setImageResource(R.drawable.ic_volume);
indicatorTextView.setText(index * 100 / maxVolume + "%");
// Show indicator. It will be hidden once onGestureDone will be called
showIndicator();
}
/**
* Get the current volume value of the media stream
*
* @param audioManager object
* @return the integer value
*/
private static int getMediaVolume(@NonNull final AudioManager audioManager) {
return audioManager.getStreamVolume(AudioManager.STREAM_MUSIC);
}