AVPlayerLayer没有绑定到UIView框架

Question

我正在尝试将AVPlayerLayer添加到UIView

    self.player = AVPlayer(URL: NSURL(fileURLWithPath: path!))
    self.playerLayer = AVPlayerLayer(player: player);
    self.playerLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
    self.playerLayer.frame =  ctrVideo.bounds;
    self.ctrVideo.layer.addSublayer(playerLayer);
    player.play();

这是视频的容器（蓝色）：

约束：

最后结果：

我无法弄清楚为什么视频没有绑定到UIVIew坐标。 如果我把它绑定到控制器的超级视图中，那就没关系。

Answer 1

当视图的帧发生变化时，子图层不会自动调整大小，您必须手动完成。 您可以将UIView子类化以使其更容易。

class VideoContainerView: UIView {
  var playerLayer: CALayer?
  override func layoutSublayersOfLayer(layer: CALayer) {
    super.layoutSublayersOfLayer(layer)
    playerLayer?.frame = self.bounds
  }
}

然后在你的代码中：

self.player = AVPlayer(URL: NSURL(fileURLWithPath: path!))
self.playerLayer = AVPlayerLayer(player: player);
self.playerLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
self.playerLayer.frame =  ctrVideo.bounds;
self.ctrVideo.layer.addSublayer(playerLayer);
self.ctrVideo.playerLayer = playerLayer;
player.play();

只需确保将“ctrVideo”的类从UIView更改为VideoContainerView。

Answer 2

我在viewDidLoad事件中添加AVPlayerLayer ...在约束适用之前。

Answer 3

这是AVPlayerLayer -backed视图，它试图保持其宽高比。

PlayerView.h：

@interface PlayerView : UIView

@property (strong, nonatomic) AVPlayerLayer *layer;

@end

PlayerView.m：

@interface PlayerView ()

@property (strong, nonatomic) NSLayoutConstraint *aspectConstraint;

@end

@implementation PlayerView

@dynamic layer;

+ (Class)layerClass {
    return [AVPlayerLayer class];
}

- (instancetype)init {
    self = [super init];
    if (self) {
        self.userInteractionEnabled = NO;

        [self addObserver:self forKeyPath:@"layer.videoRect" options:NSKeyValueObservingOptionInitial|NSKeyValueObservingOptionNew context:nil];
    }
    return self;
}

- (void)dealloc {
    [self removeObserver:self forKeyPath:@"layer.videoRect"];
}

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary<NSKeyValueChangeKey,id> *)change context:(void *)context {
    if ([keyPath isEqualToString:@"layer.videoRect"]) {
        CGSize size = [change[NSKeyValueChangeNewKey] CGRectValue].size;
        if (change[NSKeyValueChangeNewKey] && size.width && size.height) {
            self.aspectConstraint.active = NO;
            self.aspectConstraint = [self.widthAnchor constraintEqualToAnchor:self.heightAnchor multiplier:size.width / size.height];
            self.aspectConstraint.priority = UILayoutPriorityDefaultHigh;
            self.aspectConstraint.active = YES;
        }
        else {
            self.aspectConstraint.active = NO;
        }
    }
}

@end

Answer 4

这是@almas在Swift 4中的绝佳答案

class VideoContainerView: UIView {    
    var playerLayer: CALayer?

    override func layoutSublayers(of layer: CALayer) {
        super.layoutSublayers(of: layer)
        playerLayer?.frame = self.bounds
    }
}