iOS MediaPlayer Remote control events not working - ios

Question

I'am trying to add remote control events to a music player app, but can't get it working.
Some facts:
I'm using [MPMusicPlayerController applicationMusicPlayer];
I added Audio, AirPlay and Picture in Picture background modes;
The example is playing audio;
It does not receive remote notifications from the lock screen and control center;
I've made an example project which can be downloaded here:
example project
The main source:
#import "ViewController.h"
#import <MediaPlayer/MPMediaPickerController.h>
#import <MediaPlayer/MPMediaQuery.h>
#import <MediaPlayer/MediaPlayer.h>
#interface ViewController ()
#property (strong, nonatomic) MPMusicPlayerController *MusicPlayer;
#property (strong, nonatomic) MPMediaItemCollection *MusicPlayerSongs;
#end
#implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
_MusicPlayerSongs = [MPMediaItemCollection alloc];
_MusicPlayer = [MPMusicPlayerController applicationMusicPlayer];
[_MusicPlayer setShuffleMode: MPMusicShuffleModeOff];
[_MusicPlayer setRepeatMode: MPMusicRepeatModeNone];
[_MusicPlayer beginGeneratingPlaybackNotifications];
}
-(void)viewDidAppear:(BOOL)animated{
[super viewDidAppear:animated];
NSMutableArray *selectedTracks = [NSMutableArray new];
//Find all tracks that contains an 'a'
MPMediaPropertyPredicate *songPredicate =
[MPMediaPropertyPredicate predicateWithValue:#"a"
forProperty:MPMediaItemPropertyTitle
comparisonType:MPMediaPredicateComparisonContains];
MPMediaQuery *mediaQuery = [[MPMediaQuery alloc] init];
[mediaQuery addFilterPredicate:songPredicate];
[selectedTracks addObjectsFromArray:[mediaQuery items]];
NSLog(#"Number of tracks containing an 'a': %lu",(unsigned long)selectedTracks.count);
self.MusicPlayerSongs = [[MPMediaItemCollection alloc]initWithItems:selectedTracks];
[self.MusicPlayer setQueueWithItemCollection:self.MusicPlayerSongs];
[self.MusicPlayer play];
[self.MusicPlayer beginGeneratingPlaybackNotifications];
[self basicSetup];
[self updateNowPlayingCenter];
}
- (void)basicSetup {
//Listen to remote control events
[MPRemoteCommandCenter sharedCommandCenter].previousTrackCommand.enabled = NO;
[MPRemoteCommandCenter sharedCommandCenter].nextTrackCommand.enabled = NO;
[MPRemoteCommandCenter sharedCommandCenter].playCommand.enabled = YES;
[MPRemoteCommandCenter sharedCommandCenter].pauseCommand.enabled = YES;
[MPRemoteCommandCenter sharedCommandCenter].togglePlayPauseCommand.enabled = YES;
[[MPRemoteCommandCenter sharedCommandCenter].nextTrackCommand addTarget:self action:#selector(remoteNext)];
[[MPRemoteCommandCenter sharedCommandCenter].previousTrackCommand addTarget:self action:#selector(remotePrevious)];
[[MPRemoteCommandCenter sharedCommandCenter].playCommand addTarget:self action:#selector(remotePlay)];
[[MPRemoteCommandCenter sharedCommandCenter].pauseCommand addTarget:self action:#selector(remotePlay)];
[[MPRemoteCommandCenter sharedCommandCenter].togglePlayPauseCommand addTarget:self action:#selector(remoteTogglePlayState)];
[[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
}
-(void)remotePlay{
NSLog(#"remotePlay");
[self.MusicPlayer play];
}
-(void)remoteNext{
NSLog(#"remoteNext");
[self.MusicPlayer skipToNextItem];
[self updateNowPlayingCenter];
}
-(void)remotePrevious{
NSLog(#"remotePrevious");
[self.MusicPlayer skipToPreviousItem];
[self updateNowPlayingCenter];
}
-(void)remotePause{
NSLog(#"remotePause");
[self.MusicPlayer pause];
}
-(void)remoteTogglePlayState{
NSLog(#"remoteTogglePlayState");
if([self.MusicPlayer playbackState] == MPMusicPlaybackStatePlaying){
[self.MusicPlayer pause];
}else{
[self.MusicPlayer play];
}
}
-(void)updateNowPlayingCenter{
MPNowPlayingInfoCenter *center = [MPNowPlayingInfoCenter defaultCenter];
NSMutableDictionary *songInfo = [NSMutableDictionary dictionaryWithDictionary:#{
MPMediaItemPropertyArtist: [self.MusicPlayer nowPlayingItem].artist,
MPMediaItemPropertyTitle: [self.MusicPlayer nowPlayingItem].title,
MPMediaItemPropertyAlbumTitle: [self.MusicPlayer nowPlayingItem].albumTitle,
}];
center.nowPlayingInfo = songInfo;
}
I just can't figure out why it is not working :(
PROGRESS UPDATE'S
What I found out so far, if I reboot my iPhone, it works. But every time after that it won't.
The lock screen and control center both show the right track, but still can't control the app.

Answer 1

Not sure if this helps you at all, but here is how I received any changes (in Swift).
override func viewDidLoad() {
super.viewDidLoad()
NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(self.getNowPlayingItem), name: MPMusicPlayerControllerNowPlayingItemDidChangeNotification, object: nil)
player.beginGeneratingPlaybackNotifications()
}
deinit {
player.endGeneratingPlaybackNotifications()
NSNotificationCenter.defaultCenter().removeObserver(self)
}
It is necessary to (addObserver and beginGeneratingPlaybackNotifications), but also to (removeObserver and endGeneratingPlaybackNotification). I am not yet familiar with remote control events, but you may want to try ending those notifications as well. Hope this helps!