我正在尝试构建一个非常简单的无线电流媒体应用程序，它存储一个网络电台网址列表，可以选择这些网址来传输音频;使用服务允许在应用程序未激活时继续播放+通知控制。
我需要的控件非常简单：播放/暂停和停止，这应该会终止服务并在清除通知或在应用程序中按下停止按钮时引发。
我为大量代码道歉，但这就是我所处的位置：
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);
}
}
}
这是通过Google的媒体播放，Android文档和UAMP等示例应用以及其他在线示例的讲座来整理的。
目前的代码：启动，似乎设置了音频，但似乎暂停，停止和销毁，也破坏了通知。在应用程序中没有任何通知，也没有音频播放。这是一个logcat：
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开发并不完全熟悉。如果有人可以提供任何帮助，我们将非常感激。
答案 0 :(得分：3)
以下是代码中调用的方法链：
startForeground(NOTIFICATION_ID, buildNotification())方法称为buildNotification()方法通过方法getActionIntent(CMD_PAUSE) getActionIntent()方法调用方法PendingIntent.getService(getApplicationContext(), 0, s, 0) 问题在于，您正在通过一种方法获取PendingIntent并立即启动服务 - PendingIntent.getService()，根据文档：
检索将启动服务的PendingIntent，例如调用 {@link Context＃startService Context.startService（）}。开始 给予服务的参数将来自Intent的附加内容。
当您的音频开始播放时，它会创建通知，获取CMD_PAUSE操作的待处理意图，此待处理意图启动服务，调用handleIntent()方法，并通过待处理意图和您的音频设置操作然后暂停...
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)
有关详细信息，请参阅MediaButtonReceiver documentation。
当媒体服务发生媒体事件（例如按暂停按钮）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)
}
您需要找到一种向服务传递新URI的不同方式，例如使用MediaBrowser - 或更简单的方法，绑定到服务并调用方法来刷新活动中的URI。你不应该从你的活动中调用startService（）来触发onStartCommand（）。