iOS能够在不等待AVPlayerItem的情况下播放AVPlayer
我注意到我几乎可以立即在我的iOS能够在不等待AVPlayerItem的情况下播放AVPlayer,ios,swift,avplayer,Ios,Swift,Avplayer,我注意到我几乎可以立即在我的AVPlayer上发送播放消息,而无需等待AVPlayerItem中的“状态”。我对此有点困惑。为什么不马上玩呢 大多数示例显示在AVPlayerItem的“状态”键上添加观察者。下面是一些代码: self.asset!.loadValuesAsynchronouslyForKeys(keys, completionHandler: { dispatch_async(dispatch_get_main_queue(), { var error
AVPlayer
上发送播放消息,而无需等待AVPlayerItem中的“状态”。我对此有点困惑。为什么不马上玩呢
大多数示例显示在AVPlayerItem的“状态”键上添加观察者。下面是一些代码:
self.asset!.loadValuesAsynchronouslyForKeys(keys, completionHandler: {
dispatch_async(dispatch_get_main_queue(), {
var error:NSError?
for key in keys {
var status = self.asset!.statusOfValueForKey(key, error: &error)
}
var status = self.asset!.statusOfValueForKey("playable", error: &error)
if status == AVKeyValueStatus.Loaded {
playerItem = AVPlayerItem(asset: self.asset)
playerItem!.addObserver(self, forKeyPath: "status", options: NSKeyValueObservingOptions.Initial, context: itemContext)
self.player = AVPlayer(playerItem: playerItem)
playerLayer = AVPlayerLayer(player: self.player)
playerLayer!.videoGravity = AVLayerVideoGravityResizeAspectFill
playerLayer!.frame = self.view!.bounds
self.view.layer.addSublayer(playerLayer)
//self.player!.play() [This seems to work!]
} else {
println("Error in async load of keys")
}
})
})
示例显示,我需要实现一个观察器,它等待从AVPlayerItem
获取状态,然后调用AVPlayer上的play
override func observeValueForKeyPath(keyPath: String!, ofObject object: AnyObject!, change: NSDictionary!, context: CMutableVoidPointer) {
dispatch_async(dispatch_get_main_queue(), {
self.player!.play()
})
super.observeValueForKeyPath(keyPath, ofObject: object, change: change, context: context)
}
关于这一点还有一些其他问题,但没有人解释为什么不必等待AVPlayerItem上的“状态”键就可以播放播放器,因为播放数据可能还没有准备好(网络状况不佳) 这就是为什么玩家决定何时玩,这就是为什么你们应该观察AVPlayerStatusReadyToPlay案例的状态