Question

我使用AVSyncronizedLayer将项目设置为测试，以便在电影播放时在屏幕上移动红线（CALayer）。

执行此操作时，我引用了答案given here并包含了该解决方案，但视频播放时动画无法启动。

如果有人有任何想法我会出错，那会非常有帮助。代码是：

- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.

//create the red line sublayer
redLine = [CALayer layer];
redLine.backgroundColor = [UIColor redColor].CGColor;
redLine.frame = CGRectMake(engravingControl.frame.origin.x, engravingControl.center.y - (engravingControl.frame.size.height/2), 3, engravingControl.frame.size.height);


//create the AVplayer object
NSURL *fileURL = [[NSBundle mainBundle] URLForResource:@"IMG_1306" withExtension:@"mov"];
AVURLAsset *asset = [AVURLAsset URLAssetWithURL:fileURL options:nil];
AVPlayerItem *playerItem = [AVPlayerItem playerItemWithAsset:asset];

AVPlayer *player = [AVPlayer playerWithPlayerItem:playerItem];
AVPlayerLayer *playerLayer = [AVPlayerLayer playerLayerWithPlayer:player];
playerLayer.frame = CGRectMake(0, 0,400,300);
playerLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;

//add the subViews
[self.view.layer addSublayer:playerLayer];
[self.view.layer addSublayer:redLine];

CABasicAnimation *redLineMove;  
redLineMove=[CABasicAnimation animationWithKeyPath:@"transform.translation.x"];
redLineMove.duration=10;
redLineMove.fromValue=[NSNumber numberWithFloat:engravingControl.frame.origin.x];
redLineMove.toValue=[NSNumber numberWithFloat:engravingControl.frame.size.width + engravingControl.frame.origin.x];
redLineMove.beginTime = AVCoreAnimationBeginTimeAtZero;


//create the sync layer
AVSynchronizedLayer *syncLayer = [AVSynchronizedLayer     synchronizedLayerWithPlayerItem:playerItem];
[syncLayer addSublayer:redLine];
[redLine addAnimation:redLineMove forKey:@"redLineMove"];

[self.view.layer addSublayer:syncLayer];

[player play];

}

Answer 1

我发现了一个解决方案。如果您没有以下代码行：

animation.removedOnCompletion = NO;

然后动画永远不会开始（我认为在电影开始播放之前它已被CA删除）。

添加它，它可以正常工作。

使用AVSynchronizedLayer时，动画无法启动

1 个答案: