swift 3错误:输入'AVLayerVideoGravity'没有成员'resizeAspectFill'

Question

我正在使用Swift 3在iOS应用程序上工作,我在后台播放视频.我的代码完全正常,直到随机出现错误信息:

类型AVLayerVideoGravityaka(NSString)没有成员resizeAspectFill

出现.我无法弄清楚为什么resizeAspectFill不再被识别.有什么我想念的吗？我已经尝试过清理我的项目,但这并没有解决任何问题.任何帮助将不胜感激:)下面是代码:

import Foundation
import AVFoundation
import UIKit

class HomeViewController: UIViewController {
// MARK: Properties
var avPlayer: AVPlayer!
var avPlayerLayer: AVPlayerLayer!
var paused: Bool = false

var enterButton: UIButton! = UIButton()

override func viewDidLoad() {
    super.viewDidLoad()
    self.title = "Welcome"

    let theURL = Bundle.main.url(forResource:"hannah", withExtension: "mp4")

    avPlayer = AVPlayer(url: theURL!)
    avPlayerLayer = AVPlayerLayer(player: avPlayer)
    avPlayerLayer.videoGravity = AVLayerVideoGravity.resizeAspectFill

    avPlayer.volume = 0
    avPlayer.actionAtItemEnd = .none

    avPlayerLayer.frame = view.layer.bounds
    view.backgroundColor = .clear
    view.layer.insertSublayer(avPlayerLayer, at: 0)

    NotificationCenter.default.addObserver(self,
                                           selector: #selector(playerItemDidReachEnd(notification:)),
                                           name: NSNotification.Name.AVPlayerItemDidPlayToEndTime,
                                           object: avPlayer.currentItem)

Answer 1

从AVPlayerLayer的文档(遗憾的是链接重定向到Swift 4版本.要查看更改,请在右上角启用Show API更改).

视频重力决定了视频内容在播放器图层范围内的缩放或拉伸方式.播放器图层支持以下视频重力值:

• AVLayerVideoGravityResizeAspect

• AVLayerVideoGravityResizeAspectFill

• AVLayerVideoGravityResize

默认值为AVLayerVideoGravityResizeAspect.

您指的枚举案属于Swift 4