xcode 在 iOS AVPlayer 中，似乎缺少 addPeriodicTimeObserverForInterval
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In iOS AVPlayer, addPeriodicTimeObserverForInterval seems to be missing
提问by S'rCat
I'm trying to setup AVPlayer.addPeriodicTimeObserverForInterval(). Has anyone used this successfully?
我正在尝试设置AVPlayer.addPeriodicTimeObserverForInterval(). 有没有人成功使用过这个？
I'm using Xcode 8.1, Swift 3
我使用的是 Xcode 8.1、Swift 3
采纳答案by Rajat
回答by Yuchen Zhong
The accepted answer makes it feel like that you can assign the return value to a local variable and ignore it. But according to the doc, it is actually important the hold on strong reference to the return value and removeTimeObserver(_ :).
接受的答案让人感觉您可以将返回值分配给局部变量并忽略它。但根据doc，保持对返回值和的强引用实际上很重要removeTimeObserver(_ :)。
You must maintain a strong reference the returned value as long as you want the time observer to be invoked by the player. Each invocation of this method should be paired with a corresponding call to removeTimeObserver(:) . Releasing the observer object without invoking removeTimeObserver(:) will result in undefined behaviour.
只要您希望玩家调用时间观察器，就必须维护返回值的强引用。此方法的每次调用都应与对 removeTimeObserver( :)的相应调用配对。在不调用 removeTimeObserver(:) 的情况下释放观察者对象将导致未定义的行为。
So I would do:
所以我会这样做：
if let ob = self.observer {
player.removeTimeObserver(ob)
}
let interval = CMTimeMake(1, 4) // 0.25 (1/4) seconds
self.observer = player.addPeriodicTimeObserver(forInterval: interval, queue: DispatchQueue.main) { [weak self] time in
...
}
