ios - Swift:Int 不可转换为 '@lvalue inout _'

Question

我在 UIViewController 类之外声明上下文和关键变量

// player item contexts
private let PlayerItemStatusContext = 0

// player item keys
private let PlayerItemStatusKey = "status"
...
if status == AVKeyValueStatus.Loaded {
                self.playerItem = AVPlayerItem(asset: asset)
                self.playerItem?.addObserver(self, forKeyPath: PlayerItemStatusKey, options: NSKeyValueObservingOptions.Initial, context: &PlayerItemStatusContext)
                //self.player = AVPlayer(playerItem: self.playerItem!)
                //self.previewView.layer = self.player

            }

addobserver 行不断抛出错误:'Int' is not convertible to '@lvalue inout _' 我不明白这一点，也不知道如何修复它。谢谢

Answer 1

上下文必须是一个var。您不能将 let 作为 inout 参数传递。