ios11 - NSUnknownKeyException : was sent to an object that is not KVC-compliant for the "player" property

Question

我已将代码更新为在Xcode 9中快速运行4。在此之前，它可以正常工作。但是现在AVplayer崩溃了，下面是崩溃的代码。

addObserver(self, forKeyPath: "player.currentItem.duration", options: [.new, .initial], context: &playerViewControllerKVOContext)

日志是

Terminating app due to uncaught exception 'NSUnknownKeyException',reason: '[ addObserver: forKeyPath:@"player.currentItem.duration" options:5 context:0x10ff74ac8] was sent to an object that is not KVC-compliant for the "player" property.'

Answer 1

Swift没有自己的键值观察器，因此对于Swift 4，我们必须添加:
@objc dynamic
在您需要观察其值的属性之前。在您的情况下，它将是AVPlayer实例。例如。:

class MyPlayerCustomView: UIView {

@objc dynamic var myPlayer: AVPlayer?

}

希望这能解决您的问题。它确实解决了我的问题!