AVPlayer 一旦移动到后台就会冻结答案

【问题标题】：AVPlayer Freezes once moved to backgroundAVPlayer 一旦移动到后台就会冻结
【发布时间】：2015-11-12 08:34:45
【问题描述】：

我有以下代码可以加载视频并循环播放。但是，当按下 home 键并返回应用程序时，视频会冻结并且不会再次播放。我觉得答案在 AppDelegate 函数中，但似乎无法让它们工作。

import UIKit
import AVKit
import AVFoundation



class ViewController: UIViewController, UIApplicationDelegate {



var videoPlayer: AVPlayer!
var playerLayer: AVPlayerLayer?



override func viewDidLoad() {
    super.viewDidLoad()
    let path = NSBundle.mainBundle().pathForResource("video", ofType:"mp4")
    let url = NSURL(fileURLWithPath: path!)
    let playerItem = AVPlayerItem(URL: url)

    self.videoPlayer = AVPlayer(playerItem: playerItem)
    self.playerLayer = AVPlayerLayer(player: self.videoPlayer)
    self.playerLayer!.frame = self.view.frame
    self.videoPlayer!.play()

    self.view.layer.addSublayer(self.playerLayer!)


    NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("playerDidReachEnd:"), name: AVPlayerItemDidPlayToEndTimeNotification, object:nil)
}


func playerDidReachEnd(notification: NSNotification) {
    self.videoPlayer.seekToTime(kCMTimeZero)
    self.videoPlayer.play()
}


func applicationWillResignActive(application: UIApplication) {
    videoPlayer.pause()
}


func applicationDidBecomeActive(application: UIApplication) {
    videoPlayer.play()
}


func applicationDidEnterBackground(application: UIApplication) {
    videoPlayer.pause()
}


func applicationWillEnterForeground(application: UIApplication) {
    videoPlayer.play()
}





override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }



}

这是我用来修复它的。

import UIKit
import AVKit
import AVFoundation



class ViewController: UIViewController, UIApplicationDelegate {



var videoPlayer: AVPlayer!
var playerLayer: AVPlayerLayer?



override func viewDidLoad() {
    super.viewDidLoad()
    let path = NSBundle.mainBundle().pathForResource("video", ofType:"mp4")
    let url = NSURL(fileURLWithPath: path!)
    let playerItem = AVPlayerItem(URL: url)

    self.videoPlayer = AVPlayer(playerItem: playerItem)
    self.playerLayer = AVPlayerLayer(player: self.videoPlayer)
    self.playerLayer!.frame = self.view.frame
    self.videoPlayer!.play()

    self.view.layer.addSublayer(self.playerLayer!)

    NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("continueVideo:"), name: "continueVideo", object: nil)


    NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("playerDidReachEnd:"), name: AVPlayerItemDidPlayToEndTimeNotification, object:nil)
}


func playerDidReachEnd(notification: NSNotification) {
    self.videoPlayer.seekToTime(kCMTimeZero)
    self.videoPlayer.play()
}

func continueVideo(notification: NSNotification) {
    self.videoPlayer.play()
}

func applicationWillResignActive(application: UIApplication) {
    videoPlayer.pause()
}


func applicationDidBecomeActive(application: UIApplication) {
    videoPlayer.play()
}


func applicationDidEnterBackground(application: UIApplication) {
    videoPlayer.pause()
}


func applicationWillEnterForeground(application: UIApplication) {
    videoPlayer.play()
}





override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }



}

还有应用委托部分

import UIKit


@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

var window: UIWindow?


func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {

    return true
}

func applicationWillResignActive(application: UIApplication) {


}

func applicationDidEnterBackground(application: UIApplication) {


}

func applicationWillEnterForeground(application: UIApplication) {
    NSNotificationCenter.defaultCenter().postNotificationName ("continueVideo", object:nil)
}

func applicationDidBecomeActive(application: UIApplication) {

}

func applicationWillTerminate(application: UIApplication) {

}


}

【问题讨论】：

标签： xcode swift swift2 xcode7 tvos

【解决方案1】：

这是一个简单的修复，您需要创建一个NSNotification 并从您的AppDelegate 调用它：

func applicationWillEnterForeground(application: UIApplication) {
     NSNotificationCenter.defaultCenter().postNotificationName("continueVideo", object: nil)
}

SWIFT3 更新

func applicationWillEnterForeground(_ application: UIApplication) {
    // NOTE: Notification.Name raw value should be global 
    NotificationCenter.default.post(name: Notification.Name(rawValue: "com.yourappname.continueVideo"), object:self)
}

然后以正常方式接收该通知：

NSNotificationCenter.defaultCenter().addObserver(self, selector: "<funcName>:", name: "continueVideo", object: nil)

SWIFT3 更新

NotificationCenter.default.addObserver(self, selector: #selector(<funcName>), name: Notification.Name(rawValue: "com.yourappname.continueVideo"), object: nil)

【讨论】：

不太确定如何接收通知？那会在视图控制器中吗？ swift中的appdelegate部分也是？
你已经在你的ViewDidLoad 中添加了一个Notification 已经添加了这个监听器，确保你创建了一个函数并改变了选择器（突出显示的）
您将在主文件夹中有一个标准的 AppDelegate.swift 文件。 func applicationWillEnterForeground(application: UIApplication) 应该已经在文件中了。
是的，但是当我输入您在上面输入的内容时，它一直要求分隔符。它应该更像 NSNotificationCenter.defaultCenter().postNotificationName ("continueVideo", object:nil)
是的，我明白了！非常感谢！我会为其他人更新我上面的代码。