如何关闭以前的 AVPlayer 和 AVPlayerItem

Question

我正在 Swift 中制作一个 iOS 应用程序，它在屏幕右上角的一个小层中循环播放视频，显示特定颜色项目的视频。然后用户点击屏幕上相应的彩色项目。当他们这样做时，videoName 变量会随机更改为下一种颜色并触发相应的视频。如所附代码所示，使用 AVPlayer、AVPlayerItem 提升、播放和循环播放视频没有问题。我被卡住的地方是，每当显示下一个视频时，之前的视频都会在它后面保持打开状态。另外，播放完 16 个视频后，播放器在我的 iPad 上完全消失了。我已经尝试了这个网站和其他网站上提出的许多建议，但要么 swift 发现这些建议有问题，要么根本不起作用。所以问题：在我的代码中，我该如何告诉它 "hey the next video has started to play, remove the previous video and it's layer and free up the memory so i can play as many videos as needed"？

//set variables for video play
var playerItem:AVPlayerItem?
var player:AVPlayer?

//variables that contain video file path, name and extension
var videoPath = NSBundle.mainBundle().resourcePath!
var videoName = "blue"
let videoExtension = ".mp4"

//DISPLAY VIDEO
func showVideo(){

        //Assign url path
        let url = NSURL(fileURLWithPath: videoPath+"/Base.lproj/"+videoName+videoExtension)
        playerItem = AVPlayerItem(URL: url)
        player=AVPlayer(playerItem: playerItem!)
        let playerLayer=AVPlayerLayer(player: player!)

        //setplayser location in uiview and show video
        playerLayer.frame=CGRectMake(700, 5, 350, 350)
        self.view.layer.addSublayer(playerLayer)
        player!.play()

     // Add notification to know when the video ends, then replay   it again.  THIS IS A CONTINUAL LOOP
     NSNotificationCenter.defaultCenter().addObserverForName(AVPlayerItemDidPlayToEndTimeNotification, object: player!.currentItem, queue: nil)
    { notification in
        let t1 = CMTimeMake(5, 100);
        self.player!.seekToTime(t1)
        self.player!.play()
    }

}

`

Answer 1

为什么不直接在播放器上使用 replaceCurrentItemWithPlayerItem？您将为所有视频保留同一个播放器。我认为这是一个更好的方法。

编辑： replaceCurrentItemWithPlayerItem 必须在主线程上调用

Answer 2

在继续下一首曲目之前，首先检查播放器是否有任何视频或音乐，要停止它，请执行以下检查：

Swift代码-

if player!.rate > 0 && player!.error == nil
{
    player!.pause()
    player = nil
}

Objective-C代码-

if (player.rate > 0 && !player.error)
{
    [player setRate:0.0];
}

Answer 3

我采纳了@Anupam Mishra 的Swift 代码建议。一开始它没有用，但最后我想我必须把 playerLayer 带到函数之外，并在我将播放器设置为 nil 后关闭 playerLayer。还。我没有使用毫无疑问仍然有效的 'if(player!.rate>0 ...)'，而是创建了一个变量开关来指示何时说 "kill the player AND the layer"，如下所示。它可能不漂亮，但它确实有效！ 以下内容适用于像我这样的绝对新手 - 我从这次经历中学到的东西：在我看来，ios 设备只允许将 16 层添加到 viewController（或超级图层）。所以每一层都需要在用它的播放器打开下一层之前被删除，除非你真的想要一次全部 16 层运行。 下面这段代码实际上为您做了什么：这段代码在现有 viewController 上创建了一个可调整大小的图层，并播放 您的捆绑包中的视频 无限循环。当即将调用下一个视频时，将当前视频和层完全移除，释放内存，然后播放包含新视频的新层。使用 playerLayer.frame=CGRectMake(left, top, width, height) 参数可以完全自定义视频层的大小和位置。 如何让它全部工作：假设您已经将视频添加到您的捆绑包中，请为您的按钮点击创建另一个功能。在该函数中，首先调用 'stopPlayer()' 函数，将 'videoName' 变量更改为您想要的新视频名称，然后调用 'showVideo()' 函数。（如果您需要更改视频扩展名，请将 'videoExtension' 从 let 更改为 var。

`

//set variables for video play
var playerItem:AVPlayerItem?
var player:AVPlayer?
var playerLayer = AVPlayerLayer()  //NEW playerLayer var location

//variables that contain video file path, name and extension
var videoPath = NSBundle.mainBundle().resourcePath!
var videoName = "blue"
let videoExtension = ".mp4"

var createLayerSwitch = true   /*NEW switch to say whether on not to create the layer when referenced by the closePlayer and showVideo functions*/

//DISPLAY VIDEO
func showVideo(){

    //Assign url path
    let url = NSURL(fileURLWithPath: videoPath+"/Base.lproj/"+videoName+videoExtension)
    playerItem = AVPlayerItem(URL: url)
    player=AVPlayer(playerItem: playerItem!)
    playerLayer=AVPlayerLayer(player: player!) //NEW: remove 'let' from playeLayer here.

    //setplayser location in uiview and show video
    playerLayer.frame=CGRectMake(700, 5, 350, 350)
    self.view.layer.addSublayer(playerLayer)
    player!.play()

    createLayerSwitch = false  //NEW switch to tell if a layer is already created or not.  I set the switch to false so that when the next tapped item/button references the closePlayer() function, the condition is triggered to close the player AND the layer

 // Add notification to know when the video ends, then replay it again without a pause between replays.  THIS IS A CONTINUAL LOOP
 NSNotificationCenter.defaultCenter().addObserverForName(AVPlayerItemDidPlayToEndTimeNotification, object: player!.currentItem, queue: nil)
 { notification in
    let t1 = CMTimeMake(5, 100);
    self.player!.seekToTime(t1)
    self.player!.play()
 }
}
    //NEW function to kill the current player and layer before playing the next  video
func closePlayer(){
 if (createLayerSwitch == false) {
   player!.pause()
   player = nil
   playerLayer.removefromsuperlayer()
 }
}

`

如何关闭以前的 AVPlayer 和 AVPlayerItem

How to close previous AVPlayer and AVPlayerItem

ios

swift

avplayer

avplayeritem