Swift 4.0实现视频播放、屏幕旋转、倍速播放、手势调节及锁屏面板等功能实例

在iOS应用中，视频播放是一个非常常见的功能。本文将详细讲解如何使用Swift 4.0实现视频播放、屏幕旋转、倍速播放、手势调节及锁屏面板等功能。

第一步：导入AVKit和AVFoundation框架

在项目中导入AVKit和AVFoundation框架：

import AVKit
import AVFoundation

第二步：创建AVPlayerViewController及AVPlayer

创建一个AVPlayerViewController和AVPlayer对象，用于视频播放。在视图控制器中添加AVPlayerViewController，将其作为子视图控制器：

let playerVC = AVPlayerViewController()
let player = AVPlayer(url: URL(string: "http://vjs.zencdn.net/v/oceans.mp4")!)
playerVC.player = player
addChildViewController(playerVC)
view.addSubview(playerVC.view)

第三步：自动播放

设置AVPlayerViewController的shouldAutorotate、supportedInterfaceOrientations、preferredInterfaceOrientationForPresentation和当用户锁定屏幕并有通知出现时的处理方式：

override func viewDidLoad() {
    super.viewDidLoad()
    playerVC.player?.play()
    playerVC.shouldAutorotate = true
    playerVC.supportedInterfaceOrientations = .all
    playerVC.preferredInterfaceOrientationForPresentation = .portrait
    NotificationCenter.default.addObserver(self, selector: #selector(appDidEnterBackground), name: UIApplication.didEnterBackgroundNotification, object: nil)
}

第四步：倍速播放

设置当前倍速：

@IBAction func speedDidChange(_ sender: UISlider) {
    playerVC.player?.rate = sender.value
}

第五步：屏幕旋转

更改设备方向时，更新AVPlayerViewController的视图大小和AVPlayerLayer的尺寸并重新布局：

override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
    super.viewWillTransition(to: size, with: coordinator)
    coordinator.animate(alongsideTransition: { (_) in
        let targetFrame = CGRect(x: 0, y: 0, width: size.width, height: size.height)
        let layer = self.playerVC.view.layer.sublayers?.first
        layer?.frame = targetFrame
        self.playerVC.view.frame = targetFrame
    }, completion: nil)
}

第六步：手势调节音量和亮度

为AVPlayerViewController的视图添加手势控制并调整音量和亮度：

// 添加手势控制音量、亮度和播放进度
let pan = UIPanGestureRecognizer(target: self, action: #selector(handlePanGesture(_:)))
playerVC.view.addGestureRecognizer(pan)

// 手势控制时，调节音量、亮度和播放进度
@objc func handlePanGesture(_ sender: UIPanGestureRecognizer) {
    let location = sender.location(in: playerVC.view)
    let translation = sender.translation(in: playerVC.view)

    if sender.state == .began {
        let isVertical = abs(translation.y) > abs(translation.x)
        switch isVertical {
        case true:
            // 显示音量或亮度面板
            break
        case false:
            // 跳转到指定时间，显示进度条
            break
        }
    } else if sender.state == .changed {
        let isVertical = abs(translation.y) > abs(translation.x)
        switch isVertical {
        case true:
            let changeRate = -translation.y / playerVC.view.bounds.height
            let volume = max(0, min(1, originalVolume + changeRate))
            showVolumePanel(volume)
        case false:
            let time = max(0, min(CMTimeGetSeconds(playerVC.player!.currentItem!.duration), originalTime + Double(translation.x / playerVC.view.bounds.width)))
            showProgressSlider(time)
        }
    } else if sender.state == .ended {
        hideControlPanel()
    }
}

第七步：锁屏面板

为锁定屏幕添加Now Playing标签：

let nowPlayingInfo: [String: Any] = [
    MPMediaItemPropertyTitle: "Title",
    MPMediaItemPropertyArtist: "Artist",
]
MPNowPlayingInfoCenter.default().nowPlayingInfo = nowPlayingInfo

示例1：使用本地视频文件播放

let player = AVPlayer(url: Bundle.main.url(forResource: "abc", withExtension: "mov")!)
playerVC.player = player

示例2：视频播放结束后循环播放

NotificationCenter.default.addObserver(forName: .AVPlayerItemDidPlayToEndTime, object: nil, queue: nil) { [weak self] _ in
    self?.playerVC.player?.seek(to: kCMTimeZero)
    self?.playerVC.player?.play()
}

到此，Swift 4.0实现视频播放、屏幕旋转、倍速播放、手势调节及锁屏面板等功能的实例具体步骤就介绍完毕了。