问题：
如何创建具有交互式通知的Web无线电流的Android前台服务？
荀辰钊
我正在尝试构建一个极其简单的广播流应用程序，它存储一个web广播URL列表，可以选择这些URL来流式传输音频；使用服务允许在应用程序未处于活动状态时继续播放，以避免收到通知。
我需要的控件非常简单：播放/暂停和停止，当清除通知或在应用程序中按下停止按钮时，这些控件应该会终止服务并被诱导。
我为大量代码道歉，但这就是我的目的：
public class StreamingService extends Service
implements MediaPlayer.OnPreparedListener, MediaPlayer.OnErrorListener {
// .. snipped out fields
private AudioManager.OnAudioFocusChangeListener mOnAudioFocusChangeListener =
new AudioManager.OnAudioFocusChangeListener() {
@Override
public void onAudioFocusChange(int focusChange) {
switch (focusChange) {
case AudioManager.AUDIOFOCUS_GAIN:
// set mCurrentAudioFocusState field
}
if (mMediaPlayer != null)
configurePlayerState();
}
};
private int mCurrentAudioFocusState = AUDIO_NO_FOCUS_NO_DUCK;
private final IntentFilter mAudioNoisyIntentFilter =
new IntentFilter(AudioManager.ACTION_AUDIO_BECOMING_NOISY);
private BroadcastReceiver mNoisyReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
// Pause when headphones unplugged
mMediaPlayer.pause();
}
};
private boolean mAudioNoisyReceiverRegistered = false;
@Override
public void onCreate() {
super.onCreate();
AudioManager mAudioManager = (AudioManager)
getSystemService(Context.AUDIO_SERVICE);
int result = mAudioManager.requestAudioFocus(
mOnAudioFocusChangeListener,
AudioManager.STREAM_MUSIC,
AudioManager.AUDIOFOCUS_GAIN
);
if (result != AudioManager.AUDIOFOCUS_REQUEST_GRANTED) {
stopSelf();
} else {
mCurrentAudioFocusState = AUDIO_FOCUSED;
}
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
mMediaPlayer = new MediaPlayer();
mMediaPlayer.setOnPreparedListener(this);
mMediaPlayer.setOnErrorListener(this);
mMediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
mMediaPlayer.setWakeMode(getApplicationContext(), PowerManager.PARTIAL_WAKE_LOCK);
WifiManager.WifiLock wifiLock =
((WifiManager) Objects.requireNonNull(
getApplicationContext().getSystemService(Context.WIFI_SERVICE)))
.createWifiLock(WifiManager.WIFI_MODE_FULL, "wifi_lock");
wifiLock.acquire();
try {
mMediaPlayer.setDataSource(intent.getStringExtra(STREAM_URI));
} catch (IOException e) {
e.printStackTrace();
}
mMediaPlayer.prepareAsync();
onStartIntent = intent;
return Service.START_STICKY;
}
@Override
public void onDestroy() {
mMediaPlayer.release();
}
@Nullable
@Override
public IBinder onBind(Intent intent) {
return null;
}
@Override
public boolean onError(MediaPlayer mediaPlayer, int i, int i1) {
mMediaPlayer.reset();
return true;
}
@Override
public void onPrepared(MediaPlayer mediaPlayer) {
handleIntent(onStartIntent);
}
private void handleIntent(Intent intent) {
String action = intent.getAction();
String command = intent.getStringExtra(CMD_NAME);
if (ACTION_CMD.equals(action)) {
switch (command) {
case CMD_PLAY:
registerAudioNoisyReceiver();
mMediaPlayer.start();
startForeground(NOTIFICATION_ID, buildNotification());
case CMD_PAUSE:
unregisterAudioNoisyReceiver();
mMediaPlayer.pause();
startForeground(NOTIFICATION_ID, buildNotification());
case CMD_STOP:
unregisterAudioNoisyReceiver();
mMediaPlayer.stop();
stopSelf();
}
}
}
private Notification buildNotification() {
createNotificationChannel();
NotificationCompat.Builder builder =
new NotificationCompat.Builder(getApplicationContext(), NOTIFICATION_CHANNEL);
builder
.setContentTitle(onStartIntent.getStringExtra(STREAM_TITLE))
.setContentIntent(PendingIntent.getActivity(
this,
0,
new Intent(getApplicationContext(), MainActivity.class),
0))
.setVisibility(NotificationCompat.VISIBILITY_PUBLIC)
.setDeleteIntent(getActionIntent(CMD_STOP));
builder
.setSmallIcon(android.R.drawable.ic_media_play)
.setColor(ContextCompat.getColor(this, R.color.colorPrimaryDark));
builder
.addAction(new NotificationCompat.Action(
android.R.drawable.ic_media_pause, getString(R.string.pause),
getActionIntent(CMD_PAUSE)));
builder
.setStyle(new android.support.v4.media.app.NotificationCompat.MediaStyle()
.setShowActionsInCompactView(0)
.setShowCancelButton(true)
.setCancelButtonIntent(
getActionIntent(CMD_STOP)));
return builder.build();
}
private PendingIntent getActionIntent(String action) {
Intent s = new Intent(getApplicationContext(), StreamingService.class);
s.putExtra(
STREAM_TITLE,
onStartIntent.getStringExtra(STREAM_TITLE)
);
s.putExtra(
STREAM_URI,
onStartIntent.getStringExtra(STREAM_URI)
);
s.setAction(ACTION_CMD);
s.putExtra(
CMD_NAME,
action
);
s.setPackage(getApplicationContext().getPackageName());
return PendingIntent.getService(
getApplicationContext(), 0, s, 0);
}
// snipped methods to register and unregister noisy receiver
private void configurePlayerState() {
switch(mCurrentAudioFocusState) {
case AUDIO_NO_FOCUS_CAN_DUCK:
registerAudioNoisyReceiver();
mMediaPlayer.setVolume(VOLUME_DUCK, VOLUME_DUCK);
case AUDIO_NO_FOCUS_LOST:
unregisterAudioNoisyReceiver();
mMediaPlayer.stop();
case AUDIO_NO_FOCUS_NO_DUCK:
unregisterAudioNoisyReceiver();
mMediaPlayer.pause();
case AUDIO_FOCUSED:
registerAudioNoisyReceiver();
mMediaPlayer.setVolume(VOLUME_NORMAL, VOLUME_NORMAL);
}
}
private void createNotificationChannel() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
CharSequence name = getString(R.string.channel_name);
String description = getString(R.string.channel_description);
int importance = NotificationManager.IMPORTANCE_DEFAULT;
NotificationChannel channel =
new NotificationChannel(NOTIFICATION_CHANNEL, name, importance);
channel.setDescription(description);
NotificationManager notificationManager = getSystemService(NotificationManager.class);
assert notificationManager != null;
notificationManager.createNotificationChannel(channel);
}
}
}
这是从谷歌的媒体播放讲座、Android文档、UAMP等示例应用程序和其他在线示例中整理出来的。
目前的代码是：启动，似乎设置了音频，但随后似乎暂停、停止并销毁，也销毁了通知。应用程序中不会出现通知，也不会播放音频。下面是一个日志：
05-06 12:41:21.407 1903 1994 I ActivityManager: Displayed com.ojm.pinstream/.activities.MainActivity: +727ms
05-06 12:41:23.955 1903 2517 D AudioService: Stream muted, skip playback
05-06 12:41:23.962 1903 3205 I ActivityManager: START u0 {cmp=com.ojm.pinstream/.activities.PlayActivity} from uid 10191
05-06 12:41:23.979 12786 12786 W AudioManager: Use of stream types is deprecated for operations other than volume control
05-06 12:41:23.979 12786 12786 W AudioManager: See the documentation of requestAudioFocus() for what to use instead with android.media.AudioAttributes to qualify your playback use case
05-06 12:41:23.980 1903 3205 I MediaFocusControl: requestAudioFocus() from uid/pid 10191/12786 clientId=android.media.AudioManager@6badb4bcom.ojm.pinstream.services.StreamingService$1@3626928 callingPack=com.ojm.pinstream req=1 flags=0x0 sdk=27
05-06 12:41:23.986 12786 12786 W MediaPlayer: Use of stream types is deprecated for operations other than volume control
05-06 12:41:23.986 12786 12786 W MediaPlayer: See the documentation of setAudioStreamType() for what to use instead with android.media.AudioAttributes to qualify your playback use case
05-06 12:41:23.990 12786 12786 V MediaHTTPService: MediaHTTPService(android.media.MediaHTTPService@9e12641): Cookies: null
05-06 12:41:23.992 1808 25066 D NuPlayerDriver: NuPlayerDriver(0xe8513800) created, clientPid(12786)
05-06 12:41:23.996 12786 12808 V MediaHTTPService: makeHTTPConnection: CookieManager created: java.net.CookieManager@5cb47e6
05-06 12:41:23.997 12786 12808 V MediaHTTPService: makeHTTPConnection(android.media.MediaHTTPService@9e12641): cookieHandler: java.net.CookieManager@5cb47e6 Cookies: null
05-06 12:41:24.005 12786 12808 D NetworkSecurityConfig: No Network Security Config specified, using platform default
05-06 12:41:24.053 1903 4685 E NotificationService: Suppressing notification from package by user request.
05-06 12:41:24.056 1903 1966 E NotificationService: Suppressing notification from package by user request.
05-06 12:41:24.076 12786 12791 I zygote64: Do partial code cache collection, code=60KB, data=45KB
05-06 12:41:24.076 12786 12791 I zygote64: After code cache collection, code=60KB, data=45KB
05-06 12:41:24.078 12786 12791 I zygote64: Increasing code cache capacity to 256KB
05-06 12:41:24.203 1903 1994 I ActivityManager: Displayed com.ojm.pinstream/.activities.PlayActivity: +203ms
05-06 12:41:24.227 12786 12807 D OpenGLRenderer: endAllActiveAnimators on 0x7bd8b64c00 (ListView) with handle 0x7be64b8340
05-06 12:41:27.025 1903 8861 E NotificationService: Suppressing notification from package by user request.
05-06 12:41:27.031 1903 1966 E NotificationService: Suppressing notification from package by user request.
05-06 12:41:28.257 5051 5051 V ApiRequest: Performing request to https://127.0.0.1:8384/rest/events?since=0&limit=1
05-06 12:41:28.322 5051 5051 D EventProcessor: Reading events starting with id 1675
05-06 12:41:28.322 5051 5051 V ApiRequest: Performing request to https://127.0.0.1:8384/rest/events?since=1675&limit=0
05-06 12:41:28.733 1903 8861 D WificondControl: Scan result ready event
05-06 12:41:29.020 1808 12827 D GenericSource: stopBufferingIfNecessary_l, mBuffering=0
05-06 12:41:29.020 1808 12818 D NuPlayerDriver: notifyListener_l(0xe8513800), (1, 0, 0, -1), loop setting(0, 0)
05-06 12:41:29.039 1903 3205 V MediaRouterService: restoreBluetoothA2dp(false)
05-06 12:41:29.039 1711 6225 D AudioPolicyManagerCustom: setForceUse() usage 1, config 10, mPhoneState 0
05-06 12:41:29.040 1808 2811 D NuPlayerDriver: start(0xe8513800), state is 4, eos is 0
05-06 12:41:29.041 1808 12818 I GenericSource: start
05-06 12:41:29.061 1808 12834 I OMXClient: Treble IOmx obtained
05-06 12:41:29.061 1812 1902 I OMXMaster: makeComponentInstance(OMX.google.mp3.decoder) in omx@1.0-service process
05-06 12:41:29.067 1812 1902 E OMXNodeInstance: setConfig(0xf362a720:google.mp3.decoder, ConfigPriority(0x6f800002)) ERROR: Undefined(0x80001001)
05-06 12:41:29.068 1808 12834 I ACodec : codec does not support config priority (err -2147483648)
05-06 12:41:29.068 1812 6179 E OMXNodeInstance: getConfig(0xf362a720:google.mp3.decoder, ConfigAndroidVendorExtension(0x6f100004)) ERROR: Undefined(0x80001001)
05-06 12:41:29.069 1808 12834 I MediaCodec: MediaCodec will operate in async mode
05-06 12:41:29.081 1808 2811 D NuPlayerDriver: pause(0xe8513800)
05-06 12:41:29.081 1808 2811 D NuPlayerDriver: notifyListener_l(0xe8513800), (7, 0, 0, -1), loop setting(0, 0)
05-06 12:41:29.082 1903 1966 E NotificationService: Suppressing notification from package by user request.
05-06 12:41:29.082 1903 8861 V MediaRouterService: restoreBluetoothA2dp(false)
05-06 12:41:29.084 1711 6225 D AudioPolicyManagerCustom: setForceUse() usage 1, config 10, mPhoneState 0
05-06 12:41:29.097 1808 2811 D NuPlayerDriver: stop(0xe8513800)
05-06 12:41:29.097 1808 2811 D NuPlayerDriver: notifyListener_l(0xe8513800), (8, 0, 0, -1), loop setting(0, 0)
05-06 12:41:29.101 12786 12786 V MediaPlayer: resetDrmState: mDrmInfo=null mDrmProvisioningThread=null mPrepareDrmInProgress=false mActiveDrmScheme=false
05-06 12:41:29.102 12786 12786 V MediaPlayer: cleanDrmObj: mDrmObj=null mDrmSessionId=null
05-06 12:41:29.102 1808 2811 D NuPlayerDriver: reset(0xe8513800) at state 8
05-06 12:41:29.103 1903 1903 I NotificationService: Cannot find enqueued record for key: 0|com.ojm.pinstream|576|null|10191
05-06 12:41:29.108 1808 12826 I NuCachedSource2: caching reached eos.
05-06 12:41:29.108 1903 1966 E NotificationService: Suppressing notification from package by user request.
05-06 12:41:29.117 1903 3205 E NotificationService: Suppressing notification from package by user request.
05-06 12:41:29.117 1808 12818 D NuPlayerDriver: notifyResetComplete(0xe8513800)
05-06 12:41:29.121 1903 1966 E NotificationService: Suppressing notification from package by user request.
05-06 12:41:29.123 2663 2663 W StatusBar: removeNotification for unknown key: 0|com.ojm.pinstream|576|null|10191
我对Android开发没有太多经验。如果有人能提供任何帮助，我们将不胜感激。
共有1个答案
颛孙玉石
下面是在代码中调用的方法链：
- 音频开始
start Foreground（NOTIFICATION_ID，BuildNotify（））方法被称为 方法通过getActionIntent（CMD_PAUSE）添加CMD_PAUSE操作
getActionIntent（）方法调用方法PendingIntent.getService（getApplication ationContext（），0， s，0）
问题是，您通过一个方法来获取您的PendingIntent，该方法直接启动服务-PendingIntent.getService（），根据留档：
检索将启动服务的PendingIntent，如调用{@link Context#starService Context.startService（）}。提供给服务的开始参数将来自Intent的额外内容。
当音频开始播放时，它会创建通知，获取CMD_PAUSE操作的挂起意图，该挂起意图启动服务，handleIntent（）方法通过挂起意图调用操作集，然后暂停音频。。。
根据个人经验，您应该使用以下方法进行调查：
MediaButtonReceiver.buildMediaButtonPendingIntent(context,
PlaybackStateCompat.ACTION_PLAY)
有关更多详细信息，请参阅媒体按钮接收器留档。
当媒体服务发生媒体事件（如按下暂停按钮）时，会调用onStartCommand（），因此您应该实现一个简单的回调来处理此意图：
override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
MediaButtonReceiver.handleIntent(mSession, intent)
return super.onStartCommand(intent, flags, startId)
}
您需要找到一种将新URI传递给服务的不同方式，例如使用MediaBrowser，或者更简单的方式，绑定到服务并调用一个方法来刷新活动中的URI。您不应该从触发onStartCommand（）的活动中调用startService（）。
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