将UIView的CALayer动画化为圆角

Question

我正试图为我视角的圆角设置动画。 cornerRadius属性被列为可动画，但我似乎无法让它工作。我实际上也无法获得任何其他属性的动画，但角落是我感兴趣的。这是我的代码，它非常简单：

[CATransaction begin];
[CATransaction setValue: [NSNumber numberWithFloat: 2.0f] forKey:kCATransactionAnimationDuration];

self.myView.layer.cornerRadius = 50.0f;

[CATransaction commit];

我在这里想念的是什么？角落变圆，但它是瞬间而不是2秒。

Answer 1

CABasicAnimation *anim1 = [CABasicAnimation animationWithKeyPath:@"cornerRadius"];
anim1.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
anim1.fromValue = [NSNumber numberWithFloat:0.0f];
anim1.toValue = [NSNumber numberWithFloat:50.0f];
anim1.duration = 2.0;
[self.myView.layer addAnimation:anim1 forKey:@"cornerRadius"];

Answer 2

Swift 2.2 版本：

let anim1 = CABasicAnimation(keyPath: "cornerRadius")
anim1.timingFunction = CAMediaTimingFunction.functionWithName(kCAMediaTimingFunctionLinear)
anim1.fromValue = 0
anim1.toValue = 50
anim1.duration = 2.0
myView.layer.addAnimation(anim1, forKey: "cornerRadius")

Swift 3.0 版本：

let anim1 = CABasicAnimation(keyPath: "cornerRadius")
anim1.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionLinear)
anim1.fromValue = 0
anim1.toValue = 50
anim1.duration = 2.0
myView.layer.add(anim1, forKey: "cornerRadius")

<强>更新

正如Mark所注意到的，使用#keyPath描述要设置动画的属性更清晰：

let anim1 = CABasicAnimation(keyPath: #keyPath(CALayer.cornerRadius))

Answer 3

好像你正在过度思考它。我没有使用CoreAnimation就能顺利通过。这是我做的：

UIView.animate(withDuration: animationDuration) {
    self.myView.layer.cornerRadius = 10.0
}