ios – 如何关闭以前的AVPlayer和AVPlayerItem

2019年7月28日 471次阅读

我在
Swift中制作了一个iOS应用程序,它在屏幕右上角的一个小层中循环播放视频,显示特定彩色项目的视频.然后用户点击屏幕上相应的彩色项目.当它们执行时,videoName变量随机更改为下一个颜色,并触发相应的视频.我可以使用AVPlayer,AVPlayerItem来提升,播放和循环播放视频,如附带的代码所示.

我被困住的地方是,无论何时显示下一个视频,之前的视频都会保持打开状态.此外,播放了16个视频后,播放器完全消失在我的iPad上.我已尝试过在本网站和其他网站上提出的许多建议,但要么swift发现它们有问题,要么就是不行.

所以问：在我的代码中,我怎么告诉它“嘿,下一个视频已经开始播放,删除之前的视频和它的图层并释放内存,这样我就可以播放所需数量的视频”？

//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()
    }

}

`

最佳答案 我改编了@Anupam Mishra的Swift代码建议.它最初没有工作,但最终我认为我必须将playerLayer带到该功能之外并在我将玩家设置为nil之后关闭playerLayer.也.而不是使用毫无疑问仍然有用的’if(player！.rate> 0 …)’,我创建了一个变量开关来指示何时说“杀死玩家和图层”,如下所示.它可能不漂亮,但它的工作原理！以下是像我这样的绝对新手 – 我从这次经历中学到了什么：在我看来,ios设备只允许将16层添加到viewController(或superLayer).因此,在使用其播放器打开下一个图层之前,需要删除每个图层,除非您确实希望一次运行16个图层.这个代码实际上对你来说是什么：这个代码在现有的viewController上创建一个可调整大小的层,并在无限循环中播放你的包中的视频.当即将调用下一个视频时,将完全删除当前视频和图层,释放内存,然后播放带有新视频的新图层.视频图层大小和位置可使用playerLayer.frame = CGRectMake(左,顶部,宽度,高度)参数完全自定义.如何完成所有工作：假设您已将视频添加到捆绑包中,请为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()
 }
}

`

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