Question

我正在尝试设置可以播放视频的UITableView。之前的许多SO问题都使用了MPMoviePlayer（Playing Video into UITableView，Playing video in UItableView in SWIFT，Playing Video From UITableView），现在已经在iOS 9中弃用了。使用AVFoundation的少数人之一（我是什么＆＃39 ; m using），这是一个：Play video on UITableViewCell when it is completely visible，是我从中获取大部分代码的地方。这是我的代码，在cellForRowAtIndexPath中：

 VideoCell *videoCell = (VideoCell *)[self.tableView dequeueReusableCellWithIdentifier:@"VideoCell"];

        dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0ul);
        NSURL *url = [[NSURL alloc] initWithString:urlString];

        dispatch_async(queue, ^{
        videoCell.item = [AVPlayerItem playerItemWithURL:url];

            dispatch_sync(dispatch_get_main_queue(), ^{
                videoCell.player = [[AVPlayer alloc] initWithPlayerItem:videoCell.item];
                videoCell.player.actionAtItemEnd = AVPlayerActionAtItemEndNone;

                AVPlayerLayer *playerLayer = [AVPlayerLayer playerLayerWithPlayer:videoCell.player];
                playerLayer.frame = CGRectMake(0, 0, videoCell.contentView.frame.size.width, videoCell.contentView.frame.size.height);
                [videoCell.contentView.layer addSublayer:playerLayer];
                playerLayer.videoGravity = AVLayerVideoGravityResize;
                [videoCell.player play];

            });
        });


        return videoCell;

根据我的理解，我需要在播放之前异步下载视频。我以前异步下载过图像，并且下载了＃34;其中一部分总是涉及转换NSURL - ＆gt; NSData - ＆gt; UIImage的。然后当你拥有UIImage时，你已准备好在单元格中显示它，所以你将主队列调高并调度dispas_async并执行cell.imageView.image = yourImage;在主队列上。

在这里，我有一个NSURL，但是我不太明白这里应该在主队列上执行哪些步骤，哪些步骤应该在主线程之外。我尝试了上述SO问题中的建议，但到目前为止它还没有工作。表格单元格只是加载，视频永远不会播放。我只看到第一帧。有时它的前1秒会播放，但之后它会缓冲并且不会被激活。我正在使用目前只有1个对象的表视图，所以只有1个视频可以播放，但它仍然没有播放。

我做错了什么，有人可以帮我解释一下主要线程上需要哪些部分以及哪些部分关闭？我在顶部提到的帖子中的响应者说，有很多关于此的教程，＆＃34;但在扫描谷歌时，我没有看到任何。术语＆＃34;异步＆＃34;和＆＃34; iOS＆＃34;几乎总是得到关于图像下载的搜索结果，而不是视频。但是如果存在任何教程，那么很高兴看到它。

感谢

Answer 1

以下是我用于在tableview单元格中播放视频的方法。我不确定这是最好的方法，无论如何它可以帮助你:)。

首先，我创建了一个自定义单元格。在setter方法中，我调用了一个设置AVPlayer的方法。

- (void)setUpAVPlayer
{
    @try {
        self.videoPlayer = [[AVPlayer alloc]initWithPlayerItem:self.videoPlayerItem];
    }
    @catch (NSException *exception) {
        NSLog(@"Exception : %@",exception.description);
        [self.videoPlayer replaceCurrentItemWithPlayerItem:self.videoPlayerItem];
    }


    // Setting player properties.
    playerLayer = [AVPlayerLayer playerLayerWithPlayer:self.videoPlayer];
    playerLayer.videoGravity = AVLayerVideoGravityResize;
    [self.previewImageView.layer addSublayer:playerLayer];
    self.previewImageView.clipsToBounds = YES;
    playerLayer.hidden = YES;

    [playerLayer addObserver:self forKeyPath:@"readyForDisplay" options:0 context:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(pauseAllRunningPlayers) name:@"pause" object:nil];


    // AVPlayer KVO

    [self.videoPlayer addObserver:self forKeyPath:@"rate"                            options:NSKeyValueObservingOptionNew context:kRateDidChangeKVO];
    [self.videoPlayer addObserver:self forKeyPath:@"currentItem.status"              options:NSKeyValueObservingOptionNew context:kStatusDidChangeKVO];
    [self.videoPlayer addObserver:self forKeyPath:@"currentItem.duration"            options:NSKeyValueObservingOptionNew context:kDurationDidChangeKVO];
    [self.videoPlayer addObserver:self forKeyPath:@"currentItem.loadedTimeRanges"    options:NSKeyValueObservingOptionNew context:kTimeRangesKVO];
    [self.videoPlayer addObserver:self forKeyPath:@"currentItem.playbackBufferFull"  options:NSKeyValueObservingOptionNew context:kBufferFullKVO];
    [self.videoPlayer addObserver:self forKeyPath:@"currentItem.playbackBufferEmpty" options:NSKeyValueObservingOptionNew context:kBufferEmptyKVO];
    [self.videoPlayer addObserver:self forKeyPath:@"currentItem.error"               options:NSKeyValueObservingOptionNew context:kDidFailKVO];

    [videoLoadingIndicator stopAnimating];

}

我发现在你的代码中你已经编写了像这个[videoCell.player play];

这样的播放函数

只有当玩家状态变为＆＃39; AVPlayerStatusReadyToPlay＆＃39;时才应调用播放功能。这就是我使用KVO的原因。

希望这可以帮助你：）

Answer 2

在这里，我准备了一个演示，其中根据您的要求，一旦您的单元格可见，播放器将开始播放视频，您可以参考下图来设计故事板。

//
//  ViewController.swift
//  RTLDemo
//
//  Created by iOS Test User on 06/01/18.
//  Copyright © 2018 iOS Test User. All rights reserved.
//

import UIKit
import AVKit

public struct VideoName {
    static let video1 = "video1"
    static let video2 = "video2"
}

public struct MediaType {
    static let video = 1
    static let image = 2
}

class ViewController: UIViewController {

    @IBOutlet weak var collView: UICollectionView!
    var timer: Timer?
    var isVideoPlaying: Bool = false

    // ------------------------------------------------------------------------------------------
    // MARK: -
    // MARK: - Memory management method

    // ------------------------------------------------------------------------------------------

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    // ------------------------------------------------------------------------------------------
    // MARK:
    // MARK: - Custom Methods

    // ------------------------------------------------------------------------------------------

    func initialSetup() {
        if self.timer == nil {
            self.timer = Timer.scheduledTimer(timeInterval: 1.0, target: self, selector: #selector(checkForTheVisibleVideo), userInfo: nil, repeats: true)
        }
        timer?.fire()
    }

    // ------------------------------------------------------------------------------------------

    @objc func checkForTheVisibleVideo() {
        if !isVideoPlaying {
            let visibleCell = self.collView.indexPathsForVisibleItems
            if visibleCell.count > 0 {
                for indexPath in visibleCell {
                    if self.isVideoPlaying {
                        break
                    }
                    if let cell = self.collView.cellForItem(at: indexPath) as? CustomCell,cell.mediaType == MediaType.video {
                        if cell.player == nil{
                            cell.player = AVPlayer(url: URL.init(fileURLWithPath: Bundle.main.path(forResource: VideoName.video2, ofType: "mp4")!))
                            cell.playerLayer = AVPlayerLayer.init(player: cell.player)
                            cell.playerLayer?.frame = cell.imgView.frame
                            cell.imgView.layer.addSublayer(cell.playerLayer!)
                            NotificationCenter.default.addObserver(self, selector: #selector(videoDidFinishPlaying), name: NSNotification.Name.AVPlayerItemDidPlayToEndTime, object: cell.player?.currentItem)
                            cell.player?.addPeriodicTimeObserver(forInterval: CMTime.init(seconds: 1, preferredTimescale: 1), queue: .main, using: { (time) in
                                if cell.player?.currentItem?.status == .readyToPlay {

                                    let timeDuration : Float64 = CMTimeGetSeconds((cell.player?.currentItem?.asset.duration)!)
                                    cell.lblDuration.text = self.getDurationFromTime(time: timeDuration)

                                    let currentTime : Float64 = CMTimeGetSeconds((cell.player?.currentTime())!)
                                    cell.lblStart.text = self.getDurationFromTime(time: currentTime)
                                    cell.slider.maximumValue = Float(timeDuration.rounded())
                                    cell.slider.value = Float(currentTime.rounded())
                                }
                            })
                        }
                        cell.player?.play()
                        cell.btnPlay.setImage(#imageLiteral(resourceName: "pause_video"), for: .normal)
                        self.isVideoPlaying = true
                    }
                }
            }
        }
    }

    // ------------------------------------------------------------------------------------------

    @objc func videoDidFinishPlaying() {
        self.isVideoPlaying = false
        let visibleItems: Array = self.collView.indexPathsForVisibleItems

        if visibleItems.count > 0 {

            for currentCell in visibleItems {

                guard let cell = self.collView.cellForItem(at: currentCell) as? CustomCell else {
                    return
                }
                if cell.player != nil {
                    cell.player?.seek(to: kCMTimeZero)
                    cell.player?.play()
                }
            }

        }
    }

    // ------------------------------------------------------------------------------------------

    @objc func onSliderValChanged(slider: UISlider, event: UIEvent) {
        if let touchEvent = event.allTouches?.first {
            guard let cell = self.collView.cellForItem(at: IndexPath.init(item: slider.tag, section: 0)) as? CustomCell else {
                return
            }
            switch touchEvent.phase {
            case .began:
                cell.player?.pause()
            case .moved:
                cell.player?.seek(to: CMTimeMake(Int64(slider.value), 1))
            case .ended:
                cell.player?.seek(to: CMTimeMake(Int64(slider.value), 1))
                cell.player?.play()
            default:
                break
            }
        }
    }

    // ------------------------------------------------------------------------------------------

    func getDurationFromTime(time: Float64)-> String {

        let date : Date = Date(timeIntervalSince1970: time)
        let dateFormatter = DateFormatter()
        dateFormatter.timeZone = TimeZone.init(identifier: "UTC")
        dateFormatter.dateFormat = time < 3600 ? "mm:ss" : "HH:mm:ss"
        return dateFormatter.string(from: date)
    }

    // ------------------------------------------------------------------------------------------

    @IBAction func btnPlayTapped(_ sender: UIButton) {

        let indexPath = IndexPath.init(item: sender.tag, section: 0)
        guard let cell = self.collView.cellForItem(at: indexPath) as? CustomCell else {
            return
        }
        if isVideoPlaying {
            self.isVideoPlaying = false
            cell.btnPlay.setImage(#imageLiteral(resourceName: "play_video"), for: .normal)
            cell.player?.pause()
        }else{
            if cell.player == nil {
                cell.player = AVPlayer(url: URL.init(fileURLWithPath: Bundle.main.path(forResource: VideoName.video2, ofType: "mp4")!))
                cell.playerLayer = AVPlayerLayer(player: cell.player!)
                cell.playerLayer?.frame = CGRect.init(x: 0, y: 0, width: UIScreen.main.bounds.size.width - 50, height: (UIScreen.main.bounds.size.height - 64) * 0.3)
                cell.imgView.layer.addSublayer(cell.playerLayer!)
                NotificationCenter.default.addObserver(self, selector: #selector(videoDidFinishPlaying), name: NSNotification.Name.AVPlayerItemDidPlayToEndTime, object: cell.player?.currentItem)
            }
            cell.btnPlay.setImage(#imageLiteral(resourceName: "pause_video"), for: .normal)
            cell.player?.play()
            self.isVideoPlaying = true
        }

    }

    // ------------------------------------------------------------------------------------------
    // MARK: -
    // MARK: - View life cycle methods
    // ------------------------------------------------------------------------------------------

    override func viewDidLoad() {
        super.viewDidLoad()
        self.initialSetup()
    }
}

extension ViewController: UICollectionViewDataSource, UICollectionViewDelegate,UICollectionViewDelegateFlowLayout {

    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 10
    }

    // ------------------------------------------------------------------------------------------

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = self.collView.dequeueReusableCell(withReuseIdentifier: "CustomCell", for: indexPath) as! CustomCell
        if indexPath.row % 2 == 0 {
            cell.mediaType = MediaType.image
            cell.btnPlay.isHidden = true
            cell.lblDuration.isHidden = true
            cell.lblStart.isHidden = true
            cell.slider.isHidden = true
            cell.imgView.isHidden = false
        }else{
            cell.mediaType = MediaType.video
            cell.btnPlay.isHidden = false
            cell.lblDuration.isHidden = false
            cell.lblStart.isHidden = false
            cell.slider.isHidden = false
            cell.imgView.isHidden = false
        }
        cell.btnPlay.tag = indexPath.row
        cell.slider.tag = indexPath.row
        cell.btnPlay.addTarget(self, action: #selector(btnPlayTapped(_:)), for: .touchUpInside)
        cell.slider.addTarget(self, action: #selector(self.onSliderValChanged(slider:event:)), for: .valueChanged)

        return cell
    }

    // ------------------------------------------------------------------------------------------

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        return CGSize.init(width: UIScreen.main.bounds.size.width, height: UIScreen.main.bounds.size.height / 3)
    }

    // ------------------------------------------------------------------------------------------

    func collectionView(_ collectionView: UICollectionView, didEndDisplaying cell: UICollectionViewCell, forItemAt indexPath: IndexPath) {

        guard let cellToHide = cell as? CustomCell else {
            return
        }

        if cellToHide.player != nil {
            cellToHide.player?.pause()
            cellToHide.playerLayer?.removeFromSuperlayer()
            cellToHide.player = nil
            cellToHide.btnPlay.setImage(#imageLiteral(resourceName: "play_video"), for: .normal)
            self.isVideoPlaying = false
        }

    }
}

// Custom Cell Class

class CustomCell: UICollectionViewCell {

    @IBOutlet weak var btnPlay: UIButton!
    @IBOutlet weak var lblDuration: UILabel!
    @IBOutlet weak var imgView: UIImageView!
    @IBOutlet weak var viewBack: UIView!
    @IBOutlet weak var lblStart: UILabel!
    @IBOutlet weak var slider: UISlider!

    var player: AVPlayer?
    var playerLayer: AVPlayerLayer?
    var mediaType: Int!
}

故事板参考图像，其中我创建了具有集合视图单元格的简单自定义视频播放器：

Answer 3

很快，您可以使用下面的库代码在tableView单元格中播放视频：

https://github.com/MillmanY/MMPlayerView

在uitableview单元格中播放视频

3 个答案: