Swift transform rotate Lottie 动画不工作

Swift transform rotate Lottie animatino not working

我有一个简单的LottieAnimationView,我想将它旋转90度,但是.transform没有任何影响。它正在显示,但未应用转换。

我是这样设置的:

self.view.addSubview(arrowAnimation)
arrowAnimation.translatesAutoresizingMaskIntoConstraints = false
arrowAnimation.heightAnchor.constraint(equalToConstant: screenSize.width/3).isActive = true
arrowAnimation.bottomAnchor.constraint(equalTo: introLabel.topAnchor, constant: -20).isActive = true
arrowAnimation.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
arrowAnimation.contentMode = .scaleAspectFit
arrowAnimation.transform.rotated(by: .pi / 2)
arrowAnimation.animationSpeed = 1.5
arrowAnimation.loopMode = .playOnce

知道为什么 transform 在这里不起作用吗?

以下将起作用:

arrowAnimation.transform = CGAffineTransform(rotationAngle: CGFloat.pi/2)

至于原因:

.transform.rotated(by: .pi/2) returns 一个转换,但不应用它,所以你需要改为:

arrowAnimation.transform = arrowAnimation.transform.rotated(by: .pi/2)