swift - 检测 AVPlayer 视频开始停止事件

Question

这是一段非常简单的 avplayer 代码，可以播放队列中的一小部分视频。我的问题。我实际上想在队列中的视频之间暂停。可能吗？

我确实注意到 rate 触发了两次；状态和通知一样只触发一次。

import UIKit
import AVKit
import AVFoundation

class ViewController: UIViewController {
    
    @IBOutlet weak var VideoView: UIView!
    var player:AVQueuePlayer = AVQueuePlayer()
    
    @IBAction func NextSlide(sender: AnyObject) {
        player.play()
    }
    
    override func viewDidLoad() {
        func NextSlide(sender: AnyObject) {
        }
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        
        let arrayOfPaths: [String] = ["http://192.100.1.1:8080/dino1.mov","http://192.100.1.1:8080/dino1.mov","http://192.100.1.1:8080/dino1.mov"]
        
        var shots = [AVPlayerItem]()
        
        for item in arrayOfPaths {
            let url2adopt = NSURL(string: item)
            let avAsset = AVURLAsset(URL: url2adopt!)
            let shot = AVPlayerItem(asset: avAsset)
            shots.append(shot)
        }
        
        player = AVQueuePlayer(items: shots)
        let playerLayer = AVPlayerLayer(player: player)
        playerLayer.frame = VideoView.layer.bounds
        VideoView.layer.addSublayer(playerLayer)
        player.addObserver(self, forKeyPath: "status", options: NSKeyValueObservingOptions.New, context: nil)
        player.addObserver(self, forKeyPath: "rate", options: NSKeyValueObservingOptions.New, context: nil)
        NSNotificationCenter.defaultCenter().addObserver(self, selector: "itemDidFinishPlaying:", name: AVPlayerItemDidPlayToEndTimeNotification, object: player.currentItem)
        
        player.play()
    }
    
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
    
    // catch changes to status
    override func observeValueForKeyPath(keyPath: String?, ofObject object: AnyObject?, change: [String : AnyObject]?, context: UnsafeMutablePointer<Void>) {
        if (keyPath == "rate") {
            print(player.rate)
        }
        if (keyPath == "status") {
            print(player.status)
        }
    }
    
    func itemDidFinishPlaying(notification:NSNotification) {
        print("finished")
    }
    
}

Answer 1

添加这一行:

player.addObserver(
    self, forKeyPath:"currentItem", options:.Initial, context:nil)

现在，每当当前正在播放的队列项目发生变化时，您都会收到通知。