希望问题转到正确的流。
我玩 HLS，即我使用 AVPlayer 从服务器播放混合内容（音频和纯视频）。
将应用程序移至后台后，我继续播放音频：我在 plist 中启用了此类功能，另外我确实存储了 Prev Player，禁用了视觉轨道，并将 AVPlayerLayer 设置为 nil。以下是方法：
- (void)changePlayerState:(BOOL)restored
{
if (restored && !self.storedPlayer)
return;
if (!restored){
self.storedPlayer = self.playerView.player;
[self.playerView setPlayer:nil];
} else if (self.storedPlayer) {
[self.playerView setPlayer:self.storedPlayer];
self.storedPlayer = nil;
}
AVPlayerItem *playerItem = self.playerView.playerItem;
NSArray *tracks = [playerItem tracks];
for (AVPlayerItemTrack *playerItemTrack in tracks)
{
//
if ([playerItemTrack.assetTrack hasMediaCharacteristic:AVMediaCharacteristicVisual])
playerItemTrack.enabled = restored; //
}
}
和以下一个：
- (void)setPlayer:(AVPlayer *)player
{
if (_player != player) {
[self removePlayerObservers];
_player = player;
[self configurePlayerLayer];
if (_player)
[self addPlayerObservers];
}
}
- (void)removePlayerObservers
{
if ([_player observationInfo] != nil) {
[_player removeObserver:self
forKeyPath:@"rate"
context:NPUIPlayerViewPlayerRateObservationContext];
[_player removeObserver:self
forKeyPath:@"isExternalPlaybackActive"
context:NPUIPlayerViewAirPlayVideoActiveObservationContext];
}
[self removePeriodicTimeObserver];
}
- (void)addPlayerObservers {
[_player addObserver:self
forKeyPath:@"rate"
options:NSKeyValueObservingOptionInitial | NSKeyValueObservingOptionNew
context:NPUIPlayerViewPlayerRateObservationContext];
[_player addObserver:self
forKeyPath:@"isExternalPlaybackActive"
options:NSKeyValueObservingOptionInitial | NSKeyValueObservingOptionNew
context:NPUIPlayerViewAirPlayVideoActiveObservationContext];
[self addPeriodicTimeObserver];
}
- (void)removePeriodicTimeObserver
{
if (_registeredTimeObserver) {
[_player removeTimeObserver:_registeredTimeObserver];
_registeredTimeObserver = nil;
}
}
- (void)addPeriodicTimeObserver
{
__weak NPUIPlayerView *weakSelf = self;
_registeredTimeObserver = [_player addPeriodicTimeObserverForInterval:CMTimeMakeWithSeconds(0.5f, 10) queue:dispatch_get_main_queue()
因此，在将应用程序移至后台，按主页按钮并激活控制中心（从按钮向上滑动，计算器、相机、灯光按钮在哪里）后，我可以设置正在播放的项目的标题，但苹果的播放器控件没有'不起作用：按暂停，播放不起作用，滑块也不起作用。当我按下按钮时，我确实收到了事件，但与此同时，尽管我正在调用 [player pause] 或更改速率，但它不会更改按钮。但是，当通过 Internet 访问音频时出现问题，或者声音缓冲区为空时，按钮会更改，它会暂停 UI。下面是设置现在播放媒体中心和添加命令的代码
- (void)adjustNowPlayingScreen
{
MPNowPlayingInfoCenter *infoCenter = [MPNowPlayingInfoCenter defaultCenter];
NSMutableDictionary *mDic =[NSMutableDictionary dictionary];
NSString *newTitle = self.playerTitle.text ?: self.itemToPlay.shortName ?: self.itemToPlay.name ?: @"";
if (newTitle.length)
mDic[MPMediaItemPropertyTitle] = newTitle;
AVPlayerItem * item = [self.playerView.player currentItem];
CMTime itemDuration = [self.playerView.player.currentItem duration];
if (CMTIME_IS_VALID(itemDuration) ) {
NSTimeInterval duration = CMTimeGetSeconds(itemDuration);
if (duration)
mDic[MPMediaItemPropertyPlaybackDuration] = @(duration);
}
else
{
NSTimeInterval duration = CMTimeGetSeconds([item.asset duration]);
if (!isnan(duration) && duration > 0)
mDic[MPMediaItemPropertyPlaybackDuration] = @(duration);
else {
duration = CMTimeGetSeconds([[[[self playerView] playerItem] asset] duration]);
if (!isnan(duration) && duration > 0)
mDic[MPMediaItemPropertyPlaybackDuration] = @(duration);
}
}
NSString *urlStr = self.itemToPlay.autoQualityURL ?: self.itemToPlay.lowAutoQualityURL;
if (urlStr.length)
mDic[MPMediaItemPropertyAssetURL] = urlStr;
CMTime curTime = self.playerView.playerItem.currentTime;
if (CMTIME_IS_VALID(curTime)) {
NSTimeInterval duration = CMTimeGetSeconds(curTime);
mDic[MPNowPlayingInfoPropertyElapsedPlaybackTime]= @(duration);
}
if (mDic.count) {
#warning @"HACK: Necessary to change number of played items & index"
mDic[ MPMediaItemPropertyAlbumTrackNumber] = @(1);
mDic[ MPMediaItemPropertyAlbumTrackCount] = @(1);
mDic[ MPNowPlayingInfoPropertyPlaybackRate] = @(self.playerView.isPlaying ? 1.0 : 0.0);
UIImage *img = [UIImage imageNamed:@"team_4f6ae0b99d4b856118000124"];
mDic[MPMediaItemPropertyArtwork] = [[MPMediaItemArtwork alloc]initWithImage:img];
infoCenter.nowPlayingInfo = mDic;
}
}
- (void)addRemoteCommands
{
MPRemoteCommandCenter *commandCenter = [MPRemoteCommandCenter sharedCommandCenter];
MPRemoteCommand *command = [commandCenter pauseCommand];
command.enabled = true;
[command addTarget:self action:@selector(pauseCommand:)];
command = [commandCenter playCommand];
command.enabled = true;
[command addTarget:self action:@selector(playCommand:)];
command = [commandCenter togglePlayPauseCommand];
command.enabled = true;
[command addTarget:self action:@selector(toggleCommand:)];
command = [commandCenter seekForwardCommand];
command.enabled = true;
[command addTarget:self action:@selector(seekForwardCommand:)];
command = [commandCenter seekBackwardCommand];
command.enabled = true;
[command addTarget:self action:@selector(seekBackwardCommand:)];
}
- (void)updateElapsedTime
{
MPRemoteCommandCenter *commandCenter = [MPRemoteCommandCenter sharedCommandCenter];
MPRemoteCommand *command = [commandCenter togglePlayPauseCommand];
if (!command.enabled)
return;
[self adjustNowPlayingScreen];
dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, 2);
dispatch_after(popTime, dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0), ^(void){
[self updateElapsedTime];
});
}
- (void)removeRemoteCommands
{
MPRemoteCommandCenter *commandCenter = [MPRemoteCommandCenter sharedCommandCenter];
MPRemoteCommand *command = [commandCenter pauseCommand];
command.enabled = false;
[command removeTarget:self action:@selector(pauseCommand:)];
command = [commandCenter playCommand];
command.enabled = false;
[command removeTarget:self action:@selector(playCommand:)];
command = [commandCenter togglePlayPauseCommand];
command.enabled = false;
[command removeTarget:self action:@selector(toggleCommand:)];
command = [commandCenter seekForwardCommand];
command.enabled = false;
[command removeTarget:self action:@selector(seekForwardCommand:)];
command = [commandCenter seekBackwardCommand];
command.enabled = false;
[command removeTarget:self action:@selector(seekBackwardCommand:)];
}
- (void)seekBackwardCommand:(MPRemoteCommandEvent *)event
{
NSLog(@"%@",NSStringFromClass([event class]));
}
- (void)seekForwardCommand:(MPRemoteCommandEvent *)event
{
NSLog(@"%@",NSStringFromClass([event class]));
}
- (void)pauseCommand:(MPRemoteCommandEvent *)event
{
[self pause]; //_player pause];
AVPlayerItem *playerItem = self.playerView.playerItem;
NSArray *tracks = [playerItem tracks];
for (AVPlayerItemTrack *playerItemTrack in tracks)
{
/
if ([playerItemTrack.assetTrack hasMediaCharacteristic:AVMediaCharacteristicAudible])
playerItemTrack.enabled = false; /
}
MPNowPlayingInfoCenter *infoCenter = [MPNowPlayingInfoCenter defaultCenter];
NSMutableDictionary *mDic =[NSMutableDictionary dictionaryWithDictionary:infoCenter.nowPlayingInfo];
mDic[ MPNowPlayingInfoPropertyPlaybackRate] = @(0.0);
infoCenter.nowPlayingInfo = mDic;
}
所以，我的暂停命令被调用了，我调用了AVPlayer的暂停方法。但它不会停止音频流。
而且 Slider 不起作用，因此我的 seekBackwardCommand/seekForwardCommand 没有被调用。
但正如我所说，当流结束时（音频也是），控制中心上的播放器将按钮从播放更改为暂停，即它以某种方式监听音频会话的更改。
AVAudioSessionCategoryPlayback我通过设置和设置模式调整声音类别：AVAudioSessionModeMoviePlayback
请帮助如何正确处理控制屏幕上的暂停/播放按钮，如何启用滑块？
我在 iOS9、iPhone 6 上运行我的代码。