ios – Swift中的AV Player观察者 – 消息已收到但未处理

我试图在纯粹的 Swift中实现AV Player的观察者.

我收到错误：收到信息但未处理.是因为我使用的观察者的构造函数中的对象参数是否为零？

我把我的示例代码放在下面

谢谢

player.addObserver(self,forKeyPath: "status",options:NSKeyValueObservingOptions(),context: nil)
    player.addObserver(self,forKeyPath: "playbackBufferEmpty",forKeyPath: "playbackLikelyToKeepUp",forKeyPath: "loadedTimeRanges",options: NSKeyValueObservingOptions(),context: nil)


private func deallocObservers(player: AVPlayer) {
    player.removeObserver(self,forKeyPath: "status")
    player.removeObserver(self,forKeyPath: "playbackBufferEmpty")
    player.removeObserver(self,forKeyPath: "playbackLikelyToKeepUp")

}

//observer for av play
override func observeValueForKeyPath(keyPath: String,ofObject object: AnyObject,change: [NSObject : AnyObject],context: UnsafeMutablePointer<Void>) {
        if keyPath == "status" {
            println("Change at keyPath = \(keyPath) for \(object)")
        }

        if keyPath == "playbackBufferEmpty" {
            showAlert("No internet connection!",message: "Mixmatic requires an internet connection to continue streaming.")
            println("Change at keyPath = \(keyPath) for \(object)")
        }

        if keyPath == "playbackLikelyToKeepUp" {
            println("Change at keyPath = \(keyPath) for \(object)")
        }
}

解决方法

通常,当注册的观察者解除分配并且之后触发KVO事件时,会发生此问题.为了修复你需要删除所有的观察者,在你的对象将被释放之前.

在您的情况下,您注册了4个KVO更改并仅删除了3个.以下KVO观察器在任何地方都不会被删除,并导致问题.

player.addObserver(self,context: nil)

更改您的deallocObservers：方法如下：

private func deallocObservers(player: AVPlayer) {
    player.removeObserver(self,forKeyPath: "playbackLikelyToKeepUp")
    player.removeObserver(self,forKeyPath: "loadedTimeRanges")
}