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。
使用UIView执行360度动画有以下几种不同的方法。
使用CABasicAnimation
var rotationAnimation = CABasicAnimation()
rotationAnimation = CABasicAnimation.init(keyPath: "transform.rotation.z")
rotationAnimation.toValue = NSNumber(value: (Double.pi))
rotationAnimation.duration = 1.0
rotationAnimation.isCumulative = true
rotationAnimation.repeatCount = 100.0
view.layer.add(rotationAnimation, forKey: "rotationAnimation")
下面是UIView的一个扩展函数，它处理启动和停止旋转操作:
extension UIView {
// Start rotation
func startRotation() {
let rotation = CABasicAnimation(keyPath: "transform.rotation.z")
rotation.fromValue = 0
rotation.toValue = NSNumber(value: Double.pi)
rotation.duration = 1.0
rotation.isCumulative = true
rotation.repeatCount = FLT_MAX
self.layer.add(rotation, forKey: "rotationAnimation")
}
// Stop rotation
func stopRotation() {
self.layer.removeAnimation(forKey: "rotationAnimation")
}
}
现在使用UIView。动画关闭:
UIView.animate(withDuration: 0.5, animations: {
view.transform = CGAffineTransform(rotationAngle: (CGFloat(Double.pi))
}) { (isAnimationComplete) in
// Animation completed
}
如果有人想要nates的解决方案，那么这里是一个粗略的swift翻译:
class SomeClass: UIViewController {
var animating : Bool = false
@IBOutlet weak var activityIndicatorImage: UIImageView!
func startSpinning() {
if(!animating) {
animating = true;
spinWithOptions(UIViewAnimationOptions.CurveEaseIn);
}
}
func stopSpinning() {
animating = false
}
func spinWithOptions(options: UIViewAnimationOptions) {
UIView.animateWithDuration(0.5, delay: 0.0, options: options, animations: { () -> Void in
let val : CGFloat = CGFloat((M_PI / Double(2.0)));
self.activityIndicatorImage.transform = CGAffineTransformRotate(self.activityIndicatorImage.transform,val)
}) { (finished: Bool) -> Void in
if(finished) {
if(self.animating){
self.spinWithOptions(UIViewAnimationOptions.CurveLinear)
} else if (options != UIViewAnimationOptions.CurveEaseOut) {
self.spinWithOptions(UIViewAnimationOptions.CurveEaseOut)
}
}
}
}
override func viewDidLoad() {
startSpinning()
}
}
