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。
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
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
}
Kudos to Richard J. Ross III for the idea, but I found that his code wasn't quite what I needed. The default for options, I believe, is to give you UIViewAnimationOptionCurveEaseInOut, which doesn't look right in a continuous animation. Also, I added a check so that I could stop my animation at an even quarter turn if I needed (not infinite, but of indefinite duration), and made the acceleration ramp up during the first 90 degrees, and decelerate during the last 90 degrees (after a stop has been requested):
// an ivar for your class:
BOOL animating;
- (void)spinWithOptions:(UIViewAnimationOptions)options {
// this spin completes 360 degrees every 2 seconds
[UIView animateWithDuration:0.5
delay:0
options:options
animations:^{
self.imageToMove.transform = CGAffineTransformRotate(imageToMove.transform, M_PI / 2);
}
completion:^(BOOL finished) {
if (finished) {
if (animating) {
// if flag still set, keep spinning with constant speed
[self spinWithOptions: UIViewAnimationOptionCurveLinear];
} else if (options != UIViewAnimationOptionCurveEaseOut) {
// one last spin, with deceleration
[self spinWithOptions: UIViewAnimationOptionCurveEaseOut];
}
}
}];
}
- (void)startSpin {
if (!animating) {
animating = YES;
[self spinWithOptions: UIViewAnimationOptionCurveEaseIn];
}
}
- (void)stopSpin {
// set the flag to stop spinning after one last 90 degree increment
animating = NO;
}
更新
我添加了处理请求重新开始旋转(startSpin)的能力,而之前的旋转正在结束(完成)。Github上的示例项目。
在Swift中,你可以使用以下代码进行无限旋转:
斯威夫特4
extension UIView {
private static let kRotationAnimationKey = "rotationanimationkey"
func rotate(duration: Double = 1) {
if layer.animation(forKey: UIView.kRotationAnimationKey) == nil {
let rotationAnimation = CABasicAnimation(keyPath: "transform.rotation")
rotationAnimation.fromValue = 0.0
rotationAnimation.toValue = Float.pi * 2.0
rotationAnimation.duration = duration
rotationAnimation.repeatCount = Float.infinity
layer.add(rotationAnimation, forKey: UIView.kRotationAnimationKey)
}
}
func stopRotating() {
if layer.animation(forKey: UIView.kRotationAnimationKey) != nil {
layer.removeAnimation(forKey: UIView.kRotationAnimationKey)
}
}
}
斯威夫特3
let kRotationAnimationKey = "com.myapplication.rotationanimationkey" // Any key
func rotateView(view: UIView, duration: Double = 1) {
if view.layer.animationForKey(kRotationAnimationKey) == nil {
let rotationAnimation = CABasicAnimation(keyPath: "transform.rotation")
rotationAnimation.fromValue = 0.0
rotationAnimation.toValue = Float(M_PI * 2.0)
rotationAnimation.duration = duration
rotationAnimation.repeatCount = Float.infinity
view.layer.addAnimation(rotationAnimation, forKey: kRotationAnimationKey)
}
}
停下来就像:
func stopRotatingView(view: UIView) {
if view.layer.animationForKey(kRotationAnimationKey) != nil {
view.layer.removeAnimationForKey(kRotationAnimationKey)
}
}
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。