我试图旋转一个UIImageView 360度，并在网上看了几个教程。我不能让它们都工作，UIView要么停止，要么跳转到一个新位置。
我怎样才能做到这一点呢?
我最近尝试的是:
[UIView animateWithDuration:1.0
delay:0.0
options:0
animations:^{
imageToMove.transform = CGAffineTransformMakeRotation(M_PI);
}
completion:^(BOOL finished){
NSLog(@"Done!");
}];
但如果我使用2*pi，它根本不会移动(因为它是相同的位置)。如果我尝试只做(180度)，它可以工作，但如果我再次调用这个方法，它会向后旋转。
编辑:
[UIView animateWithDuration:1.0
delay:0.0
options:0
animations:^{
[UIView setAnimationRepeatCount:HUGE_VALF];
[UIView setAnimationBeginsFromCurrentState:YES];
imageToMove.transform = CGAffineTransformMakeRotation(M_PI);
}
completion:^(BOOL finished){
NSLog(@"Done!");
}];
也不管用。它会转到180度，暂停一秒钟，然后在重新开始之前重置回0度。
这是我的快速解决方案作为一个UIView扩展。它可以被认为是任何UIImageView上UIActivityIndicator行为的模拟。
import UIKit
extension UIView
{
/**
Starts rotating the view around Z axis.
@param duration Duration of one full 360 degrees rotation. One second is default.
@param repeatCount How many times the spin should be done. If not provided, the view will spin forever.
@param clockwise Direction of the rotation. Default is clockwise (true).
*/
func startZRotation(duration duration: CFTimeInterval = 1, repeatCount: Float = Float.infinity, clockwise: Bool = true)
{
if self.layer.animationForKey("transform.rotation.z") != nil {
return
}
let animation = CABasicAnimation(keyPath: "transform.rotation.z")
let direction = clockwise ? 1.0 : -1.0
animation.toValue = NSNumber(double: M_PI * 2 * direction)
animation.duration = duration
animation.cumulative = true
animation.repeatCount = repeatCount
self.layer.addAnimation(animation, forKey:"transform.rotation.z")
}
/// Stop rotating the view around Z axis.
func stopZRotation()
{
self.layer.removeAnimationForKey("transform.rotation.z")
}
}
创建动画
- (CABasicAnimation *)spinAnimationWithDuration:(CGFloat)duration clockwise:(BOOL)clockwise repeat:(BOOL)repeats
{
CABasicAnimation *anim = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];
anim.toValue = clockwise ? @(M_PI * 2.0) : @(M_PI * -2.0);
anim.duration = duration;
anim.cumulative = YES;
anim.repeatCount = repeats ? CGFLOAT_MAX : 0;
return anim;
}
将它添加到这样的视图中
CABasicAnimation *animation = [self spinAnimationWithDuration:1.0 clockwise:YES repeat:YES];
[self.spinningView.layer addAnimation:animation forKey:@"rotationAnimation"];
这个答案有什么不同?如果你的大部分函数都返回对象，而不是在这里和那里操作一些对象，你会有更干净的代码。
我已经开发了一个闪亮的动画框架，可以节省你的时间!
使用它可以很容易地创建这个动画:
private var endlessRotater: EndlessAnimator!
override func viewDidAppear(animated: Bool)
{
super.viewDidAppear(animated)
let rotationAnimation = AdditiveRotateAnimator(M_PI).to(targetView).duration(2.0).baseAnimation(.CurveLinear)
endlessRotater = EndlessAnimator(rotationAnimation)
endlessRotater.animate()
}
要停止这个动画，只需将nil设置为endlessRotater。
如果你感兴趣，请看看:https://github.com/hip4yes/Animatics
