Question

我有一个在后台播放音频的应用程序。我正在尝试修复主屏幕（等）上音频控件（播放/暂停）的错误，不能在iOS 8.0上运行，但在iOS 7.0上运行FINE。我一直在努力弄清楚问题是什么，并且一直空洞。任何想法将不胜感激。这就是我所拥有的。

在项目设置中：我确保将UIBackgroundModes设置为audio。

在AppDelegate.h中：我有AVAudioSession* session;以及AVPlayer *audioPlayer;

的成员

在AppDelegate.m中：

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions{

self.session = [AVAudioSession sharedInstance];

NSError* error = NULL;
[self.session setCategory:AVAudioSessionCategoryPlayback error:&error];
[self.session setActive:YES error:&error];

if (error) {
    NSLog(@"AVAudioSession error: %@", [error localizedDescription]);
}

在AudioPlayerViewController.m

中

- (void)viewDidLoad {

//Get the Audio
NSURL *url = [NSURL URLWithString:self.audioUrl];
AVAsset *asset = [AVURLAsset URLAssetWithURL:url options:nil];

//Setup the player
self.playerItem = [AVPlayerItem playerItemWithAsset:asset];
appDelegate.audioPlayer = [AVPlayer playerWithPlayerItem:self.playerItem];

//Setup the "Now Playing"
NSMutableDictionary *mediaInfo = [[NSMutableDictionary alloc]init];
[mediaInfo setObject:self.title forKey:MPMediaItemPropertyTitle];
[mediaInfo setObject:self.artist forKey:MPMediaItemPropertyArtist];
[mediaInfo setObject:self.album forKey:MPMediaItemPropertyAlbumTitle];
[mediaInfo setObject:[NSNumber numberWithDouble:duration ] forKey:MPMediaItemPropertyPlaybackDuration];
[[MPNowPlayingInfoCenter defaultCenter] setNowPlayingInfo:mediaInfo];

}

// Process remote control events
- (void) remoteControlReceivedWithEvent:(UIEvent *)event {

NSLog(@"AudioPlayerViewController ... remoteControlReceivedWithEvent top ....subtype: %d", event.subtype);

if (event.type == UIEventTypeRemoteControl) {

    switch (event.subtype) {
        case UIEventSubtypeRemoteControlTogglePlayPause:
            [self togglePlayPause];
            break;
        case UIEventSubtypeRemoteControlPause:
            [self doPause];
            break;
        case UIEventSubtypeRemoteControlStop:
            [self doPause];
            break;
        case UIEventSubtypeRemoteControlPlay:
            [self doPlay];
            break;
        case UIEventSubtypeRemoteControlPreviousTrack:
            [self nextOrPrevTrack];
            break;
        case UIEventSubtypeRemoteControlNextTrack:
            [self nextOrPrevTrack];
            break;
        default:
            break;
    }
}

}

-(void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
[[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
[self becomeFirstResponder];

}

- (void)viewWillDisappear:(BOOL)animated {
[super viewWillDisappear:animated];
[[UIApplication sharedApplication] endReceivingRemoteControlEvents];
[self resignFirstResponder];

}

- (BOOL) canBecomeFirstResponder {
return YES;

}

Answer 1

终于找到了我遇到的问题。最终似乎主屏幕上远程控制的事件从未进入我的应用程序，直到我的视图控制器。我最终继承了UIWindow，因此我可以看到哪些事件正在通过链条。由于UIWindow是UIResponder，我还将- (void)remoteControlReceivedWithEvent:(UIEvent *)event添加到子类中。然后在makeKeyAndVisible中添加了：

[[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
[self becomeFirstResponder];

我启动了调试器，-(void)makeKeyAndVisible从未被调用过！然后我在我的应用代表中搜索了window成员变量，[window makeKeyAndVisible];行无处可寻！我把它添加回来（因为它应该在那里）并且presto事件正在路由到像魔法一样的正确位置。为什么这适用于某些版本的iOS而不是其他版本，没有任何其他明显的问题超出了我的范围。

希望这可以帮助将来的某个人。

Answer 2

在ViewController中添加

override func viewWillAppear(animated: Bool) {
        super.viewWillAppear(animated)

        UIApplication.sharedApplication().beginReceivingRemoteControlEvents()
        self.becomeFirstResponder()
}

override func remoteControlReceivedWithEvent(event: UIEvent) {
        // your stuff
    }

在AppDelegate中添加

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {

var error: NSError?
        AVAudioSession.sharedInstance().setCategory(AVAudioSessionCategoryPlayback, error: &error)
        AVAudioSession.sharedInstance().setActive(true, error: &error)
}

SWIFT 3

UIApplication.shared.beginReceivingRemoteControlEvents()
self.becomeFirstResponder()

do {
    try AVAudioSession.sharedInstance().setCategory(AVAudioSessionCategoryPlayback)
    try AVAudioSession.sharedInstance().setActive(true)
} catch {
    print("hmmm...")
}

在iOS 7.0设备上调用remoteControlReceivedWithEvent但不在iOS 8.0上调用

2 个答案: