UIView Infinite 360 degree rotation animation?

问题:

I\'m trying to rotate a UIImageView 360 degrees, and have looked at several tutorials online. I could get none of them working, without the UIView either stopping, or jumping to a new position.

• How can I achieve this?

The latest thing I\'ve tried is:

[UIView animateWithDuration:1.0
                      delay:0.0
                    options:0
                 animations:^{
                     imageToMove.transform = CGAffineTransformMakeRotation(M_PI);
                 } 
                 completion:^(BOOL finished){
                     NSLog(@\"Done!\");
                 }];

But if I use 2*pi, it doesn\'t move at all (since it\'s the same position). If I try to do just pi (180 degrees), it works, but if I call the method again, it rotates backwards.

EDIT:

[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!\");
                 }];

doesn\'t work either. It goes to 180 degrees, pauses for a split second, then resets back to 0 degrees before it starts again.

回答1:

Found a method (I modified it a bit) that worked perfectly for me: iphone UIImageView rotation

#import <QuartzCore/QuartzCore.h>

- (void) runSpinAnimationOnView:(UIView*)view duration:(CGFloat)duration rotations:(CGFloat)rotations repeat:(float)repeat {
    CABasicAnimation* rotationAnimation;
    rotationAnimation = [CABasicAnimation animationWithKeyPath:@\"transform.rotation.z\"];
    rotationAnimation.toValue = [NSNumber numberWithFloat: M_PI * 2.0 /* full rotation*/ * rotations * duration ];
    rotationAnimation.duration = duration;
    rotationAnimation.cumulative = YES;
    rotationAnimation.repeatCount = repeat ? HUGE_VALF : 0;

    [view.layer addAnimation:rotationAnimation forKey:@\"rotationAnimation\"];
}

回答2:

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;
}

Update

I added the ability to handle requests to start spinning again (startSpin), while the previous spin is winding down (completing). Sample project here on Github.

回答3:

Nate\'s answer above is ideal for stop and start animation and gives a better control. I was intrigued why yours didn\'t work and his does. I wanted to share my findings here and a simpler version of the code that would animate a UIView continuously without stalling.

This is the code I used,

- (void)rotateImageView
{
    [UIView animateWithDuration:1 delay:0 options:UIViewAnimationOptionCurveLinear animations:^{
        [self.imageView setTransform:CGAffineTransformRotate(self.imageView.transform, M_PI_2)];
    }completion:^(BOOL finished){
        if (finished) {
            [self rotateImageView];
        }
    }];
}

I used \'CGAffineTransformRotate\' instead of \'CGAffineTransformMakeRotation\' because the former returns the result which is saved as the animation proceeds. This will prevent the jumping or resetting of the view during the animation.

Another thing is not to use \'UIViewAnimationOptionRepeat\' because at the end of the animation before it starts repeating, it resets the transform making the view jump back to its original position. Instead of a repeat, you recurse so that the transform is never reset to the original value because the animation block virtually never ends.

And the last thing is, you have to transform the view in steps of 90 degrees (M_PI / 2) instead of 360 or 180 degrees (2*M_PI or M_PI). Because transformation occurs as a matrix multiplication of sine and cosine values.

t\' =  [ cos(angle) sin(angle) -sin(angle) cos(angle) 0 0 ] * t

So, say if you use 180-degree transformation, the cosine of 180 yields -1 making the view transform in opposite direction each time (Note-Nate\'s answer will also have this issue if you change the radian value of transformation to M_PI). A 360-degree transformation is simply asking the view to remain where it was, hence you don\'t see any rotation at all.

回答4:

In Swift, you can use the following code for infinite rotation:

Swift 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)
        }
    }
}

Swift 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)
    }
}

Stopping is like:

func stopRotatingView(view: UIView) {
    if view.layer.animationForKey(kRotationAnimationKey) != nil {
        view.layer.removeAnimationForKey(kRotationAnimationKey)
    }
}

回答5:

If all you want to do is rotate the image endlessly, this works quite well, and is very simple:

NSTimeInterval duration = 10.0f;
CGFloat angle = M_PI / 2.0f;
CGAffineTransform rotateTransform = CGAffineTransformRotate(imageView.transform, angle);

[UIView animateWithDuration:duration delay:0 options:UIViewAnimationOptionRepeat| UIViewAnimationOptionCurveLinear animations:^{
    imageView.transform = rotateTransform;
} completion:nil];

In my experience, this works flawlessly, but be sure your image is capable of being rotated around its center without any offsets, or the image animation will \"jump\" once it makes it around to PI.

To change the direction of the spin, change the sign of angle (angle *= -1).

Update Comments by @AlexPretzlav made me revisit this, and I realized that when I wrote this the image I was rotating was mirrored along both the vertical and horizontal axis, meaning the image was indeed only rotating 90 degrees and then resetting, though it looked like it was continuing to rotate all the way around.

So, if your image is like mine was, this will work great, however, if the image is not symmetrical, you\'ll notice the \"snap\" back to the original orientation after 90 degrees.

To rotate a non-symmetrical image, you\'re better off with the accepted answer.

One of these less elegant solutions, seen below, will truly rotate the image, but there may be a noticeable stutter when the animation is restarted:

- (void)spin
{
    NSTimeInterval duration = 0.5f;
    CGFloat angle = M_PI_2;
    CGAffineTransform rotateTransform = CGAffineTransformRotate(self.imageView.transform, angle);

    [UIView animateWithDuration:duration delay:0 options:UIViewAnimationOptionCurveLinear animations:^{
        self.imageView.transform = rotateTransform;
    } completion:^(BOOL finished) {
        [self spin];
    }];
}

You could also do this just with blocks, as @richard-j-ross-iii suggests, but you will get a retain loop warning since the block is capturing itself:

__block void(^spin)() = ^{
    NSTimeInterval duration = 0.5f;
    CGFloat angle = M_PI_2;
    CGAffineTransform rotateTransform = CGAffineTransformRotate(self.imageView.transform, angle);

    [UIView animateWithDuration:duration delay:0 options:UIViewAnimationOptionCurveLinear animations:^{
        self.imageView.transform = rotateTransform;
    } completion:^(BOOL finished) {
        spin();
    }];
};
spin();

回答6:

My contribution with a Swift Extension from the checked solution :

Swift 4.0

extension UIView{
    func rotate() {
        let rotation : CABasicAnimation = CABasicAnimation(keyPath: \"transform.rotation.z\")
        rotation.toValue = NSNumber(value: Double.pi * 2)
        rotation.duration = 1
        rotation.isCumulative = true
        rotation.repeatCount = Float.greatestFiniteMagnitude
        self.layer.add(rotation, forKey: \"rotationAnimation\")
    }
}

Deprecated :

extension UIView{
    func rotate() {
        let rotation : CABasicAnimation = CABasicAnimation(keyPath: \"transform.rotation.z\")
        rotation.toValue = NSNumber(double: M_PI * 2)
        rotation.duration = 1
        rotation.cumulative = true
        rotation.repeatCount = FLT_MAX
        self.layer.addAnimation(rotation, forKey: \"rotationAnimation\")
    }
}

回答7:

Use quarter turn, and increase the turn incrementally.

void (^block)() = ^{
    imageToMove.transform = CGAffineTransformRotate(imageToMove.transform, M_PI / 2);
}

void (^completion)(BOOL) = ^(BOOL finished){
    [UIView animateWithDuration:1.0
                          delay:0.0
                        options:0
                     animations:block
                     completion:completion];
}

completion(YES);

回答8:

I have found nice code in this repository,

Here is the code from it i have done small changes according to my need for speed :)

UIImageView+Rotate.h

#import <Foundation/Foundation.h>

@interface UIImageView (Rotate)
- (void)rotate360WithDuration:(CGFloat)duration repeatCount:(float)repeatCount;
- (void)pauseAnimations;
- (void)resumeAnimations;
- (void)stopAllAnimations;
@end

UIImageView+Rotate.m

#import <QuartzCore/QuartzCore.h>
#import \"UIImageView+Rotate.h\"

@implementation UIImageView (Rotate)

- (void)rotate360WithDuration:(CGFloat)duration repeatCount:(float)repeatCount
{

    CABasicAnimation *fullRotation;
    fullRotation = [CABasicAnimation animationWithKeyPath:@\"transform.rotation\"];
    fullRotation.fromValue = [NSNumber numberWithFloat:0];
    //fullRotation.toValue = [NSNumber numberWithFloat:(2*M_PI)];
    fullRotation.toValue = [NSNumber numberWithFloat:-(2*M_PI)]; // added this minus sign as i want to rotate it to anticlockwise
    fullRotation.duration = duration;
    fullRotation.speed = 2.0f;              // Changed rotation speed
    if (repeatCount == 0)
        fullRotation.repeatCount = MAXFLOAT;
    else
        fullRotation.repeatCount = repeatCount;

    [self.layer addAnimation:fullRotation forKey:@\"360\"];
}

//Not using this methods :)

- (void)stopAllAnimations
{

    [self.layer removeAllAnimations];
};

- (void)pauseAnimations
{

    [self pauseLayer:self.layer];
}

- (void)resumeAnimations
{

    [self resumeLayer:self.layer];
}

- (void)pauseLayer:(CALayer *)layer
{

    CFTimeInterval pausedTime = [layer convertTime:CACurrentMediaTime() fromLayer:nil];
    layer.speed = 0.0;
    layer.timeOffset = pausedTime;
}

- (void)resumeLayer:(CALayer *)layer
{

    CFTimeInterval pausedTime = [layer timeOffset];
    layer.speed = 1.0;
    layer.timeOffset = 0.0;
    layer.beginTime = 0.0;
    CFTimeInterval timeSincePause = [layer convertTime:CACurrentMediaTime() fromLayer:nil] - pausedTime;
    layer.beginTime = timeSincePause;
}

@end

回答9:

Here is my swift solution as a UIView extension. It could be considered as a simulation of a UIActivityIndicator behaviour on any UIImageView.

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\")
    }

}

回答10:

This was working for me:

[UIView animateWithDuration:1.0
                animations:^
{
    self.imageView.transform = CGAffineTransformMakeRotation(M_PI);
    self.imageView.transform = CGAffineTransformMakeRotation(0);
}];

回答11:

A Swift3 version:

extension UIView {

    func startRotate() {
        let rotation : CABasicAnimation = CABasicAnimation(keyPath: \"transform.rotation.z\")
        rotation.fromValue = 0
        rotation.toValue = NSNumber(value: M_PI * 2)
        rotation.duration = 2
        rotation.isCumulative = true
        rotation.repeatCount = FLT_MAX
        self.layer.add(rotation, forKey: \"rotationAnimation\")
    }

    func stopRotate() {
        self.layer.removeAnimation(forKey: \"rotationAnimation\")
    }
}

And remember to call startRotate in viewWillAppear not in viewDidLoad.

回答12:

David Rysanek\'s awesome answer updated to Swift 4:

import UIKit

extension UIView {

        func startRotating(duration: CFTimeInterval = 3, repeatCount: Float = Float.infinity, clockwise: Bool = true) {

            if self.layer.animation(forKey: \"transform.rotation.z\") != nil {
                return
            }

            let animation = CABasicAnimation(keyPath: \"transform.rotation.z\")
            let direction = clockwise ? 1.0 : -1.0
            animation.toValue = NSNumber(value: .pi * 2 * direction)
            animation.duration = duration
            animation.isCumulative = true
            animation.repeatCount = repeatCount
            self.layer.add(animation, forKey:\"transform.rotation.z\")
        }

        func stopRotating() {

            self.layer.removeAnimation(forKey: \"transform.rotation.z\")

        }   

    }
}

回答13:

You can also do the same type of animation using UIView and blocks. Here is a class extension method which can rotate the view by any angle.

- (void)rotationWithDuration:(NSTimeInterval)duration angle:(CGFloat)angle options:(UIViewAnimationOptions)options
{
    // Repeat a quarter rotation as many times as needed to complete the full rotation
    CGFloat sign = angle > 0 ? 1 : -1;
    __block NSUInteger numberRepeats = floorf(fabsf(angle) / M_PI_2);
    CGFloat quarterDuration = duration * M_PI_2 / fabs(angle);

    CGFloat lastRotation = angle - sign * numberRepeats * M_PI_2;
    CGFloat lastDuration = duration - quarterDuration * numberRepeats;

    __block UIViewAnimationOptions startOptions = UIViewAnimationOptionBeginFromCurrentState;
    UIViewAnimationOptions endOptions = UIViewAnimationOptionBeginFromCurrentState;

    if (options & UIViewAnimationOptionCurveEaseIn || options == UIViewAnimationOptionCurveEaseInOut) {
        startOptions |= UIViewAnimationOptionCurveEaseIn;
    } else {
        startOptions |= UIViewAnimationOptionCurveLinear;
    }

    if (options & UIViewAnimationOptionCurveEaseOut || options == UIViewAnimationOptionCurveEaseInOut) {
        endOptions |= UIViewAnimationOptionCurveEaseOut;
    } else {
        endOptions |= UIViewAnimationOptionCurveLinear;
    }

    void (^lastRotationBlock)(void) = ^ {
        [UIView animateWithDuration:lastDuration 
                              delay:0 
                            options:endOptions 
                         animations:^{
                             self.transform = CGAffineTransformRotate(self.transform, lastRotation);
                         } 
                         completion:^(BOOL finished) {
                             NSLog(@\"Animation completed\");   
                         }
         ];
    };

    if (numberRepeats) {
        __block void (^quarterSpinningBlock)(void) = ^{ 
            [UIView animateWithDuration:quarterDuration 
                                  delay:0 
                                options:startOptions 
                             animations:^{
                                 self.transform = CGAffineTransformRotate(self.transform, M_PI_2);
                                 numberRepeats--; 
                             } 
                             completion:^(BOOL finished) {
                                 if (numberRepeats > 0) {
                                     startOptions = UIViewAnimationOptionBeginFromCurrentState | UIViewAnimationOptionCurveLinear;
                                     quarterSpinningBlock();
                                 } else {
                                     lastRotationBlock();
                                 }NSLog(@\"Animation completed\");   
                             }
             ];

        };

        quarterSpinningBlock();
    } else {
        lastRotationBlock();
    }
}

回答14:

If anyone wanted nates\' solution but in swift, then here is a rough swift translation:

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()
    }
}

回答15:

for xamarin ios:

public static void RotateAnimation (this UIView view, float duration=1, float rotations=1, float repeat=int.MaxValue)
{
    var rotationAnimation = CABasicAnimation.FromKeyPath (\"transform.rotation.z\");
    rotationAnimation.To = new NSNumber (Math.PI * 2.0 /* full rotation*/ * 1 * 1);
    rotationAnimation.Duration = 1;
    rotationAnimation.Cumulative = true;
    rotationAnimation.RepeatCount = int.MaxValue;
    rotationAnimation.RemovedOnCompletion = false;
    view.Layer.AddAnimation (rotationAnimation, \"rotationAnimation\");
}

回答16:

This is how I rotate 360 in right direction.

[UIView animateWithDuration:1.0f delay:0.0f options:UIViewAnimationOptionRepeat|UIViewAnimationOptionCurveLinear
                     animations:^{
                         [imageIndView setTransform:CGAffineTransformRotate([imageIndView transform], M_PI-0.00001f)];
                     } completion:nil];

回答17:

@ram\'s answer was really helpful. Here\'s a Swift version of the answer.

private func rotateImageView() {

    UIView.animateWithDuration(1, delay: 0, options: UIViewAnimationOptions.CurveLinear, animations: { () -> Void in
        self.imageView.transform = CGAffineTransformRotate(self.imageView.transform, CGFloat(M_PI_2))
        }) { (finished) -> Void in
            if finished {
                self.rotateImageView()
            }
    }
}

回答18:

Create the animation

- (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;
}

Add it to a view like this

CABasicAnimation *animation = [self spinAnimationWithDuration:1.0 clockwise:YES repeat:YES];
[self.spinningView.layer addAnimation:animation forKey:@\"rotationAnimation\"];

How is this answer different? You will have way cleaner code if most of your functions returns objects instead of just manipulating some objects here and there.

回答19:

Swift 4.0

func rotateImageView()
{
    UIView.animate(withDuration: 0.3, delay: 0, options: .curveLinear, animations: {() -> Void in
        self.imageView.transform = self.imageView.transform.rotated(by: .pi / 2)
    }, completion: {(_ finished: Bool) -> Void in
        if finished {
            rotateImageView()
        }
    })
}

回答20:

There are following different ways to perform 360 degree animation with UIView.

Using 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\")

Here is an extension functions for UIView that handles start & stop rotation operations:

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\")
    }
}

Now using, UIView.animation closure:

UIView.animate(withDuration: 0.5, animations: { 
      view.transform = CGAffineTransform(rotationAngle: (CGFloat(Double.pi)) 
}) { (isAnimationComplete) in
    // Animation completed 
}

回答21:

I has developed a shiny animation framework which can save you tone of time! Using it this animation can be created very easily:

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()
}

to stop this animation simply set nil to endlessRotater.

If you are interested, please take a look: https://github.com/hip4yes/Animatics

回答22:

Swift 4,

func rotateImage(image: UIImageView) {
        UIView.animate(withDuration: 1, animations: {
            image.transform = CGAffineTransform(rotationAngle: CGFloat.pi)
            image.transform = CGAffineTransform.identity
        }) { (completed) in
            self.rotateImage()
        }
    }

Ref

回答23:

Swift :

func runSpinAnimationOnView(view:UIView , duration:Float, rotations:Double, repeatt:Float ) ->()
    {
        let rotationAnimation=CABasicAnimation();

        rotationAnimation.keyPath=\"transform.rotation.z\"

        let toValue = M_PI * 2.0 * rotations ;


        // passing it a float
        let someInterval = CFTimeInterval(duration)

        rotationAnimation.toValue=toValue;
        rotationAnimation.duration=someInterval;
        rotationAnimation.cumulative=true;
        rotationAnimation.repeatCount=repeatt;
        view.layer.addAnimation(rotationAnimation, forKey: \"rotationAnimation\")


    }

回答24:

Swift 3 :

 var rotationAnimation = CABasicAnimation()
     rotationAnimation = CABasicAnimation.init(keyPath: \"transform.rotation.z\")
     rotationAnimation.toValue = NSNumber(value: (M_PI * 2.0))
     rotationAnimation.duration = 2.0
     rotationAnimation.isCumulative = true
     rotationAnimation.repeatCount = 10.0
     view.layer.add(rotationAnimation, forKey: \"rotationAnimation\")

回答25:

let val = CGFloat(M_PI_2)

UIView.animate(withDuration: 1, delay: 0, options: [.repeat, .curveLinear], animations: {
        self.viewToRotate.transform = self.viewToRotate.transform.rotated(by: val)
})

回答26:

I think you should better add a UIVIew Category:

#import <QuartzCore/QuartzCore.h>
#import \"UIView+Rotate.h\"

Implementation UIView (Rotate)

• (void)remrotate360WithDuration:(CGFloat)duration repeatCount: (float)repeatCount
  {
      CABasicAnimation *fullRotation;
      fullRotation = [CABasicAnimation animationWithKeyPath:@\"transform.rotation\"];
      fullRotation.fromValue = [NSNumber numberWithFloat:0];
      fullRotation.toValue = [NSNumber numberWithFloat:(2*M_PI)];
      // fullRotation.toValue = [NSNumber numberWithFloat:-(2*M_PI)]; // added this minus sign as i want to rotate it to anticlockwise
      fullRotation.duration = duration;
      fullRotation.speed = 2.0f; // Changed rotation speed
      if (repeatCount == 0)
          fullRotation.repeatCount = MAXFLOAT;
      else
          fullRotation.repeatCount = repeatCount;
  
      [self.layer addAnimation:fullRotation forKey:@\"360\"];
  }
  

Not using this methods :)

• (void)remstopAllAnimations
  {
      [self.layer removeAllAnimations];
  };
  

• (void)rempauseAnimations
  {
      [self rempauseLayer:self.layer];
  }
  

• (void)remresumeAnimations
  {
      [self remresumeLayer:self.layer];
  }
  

• (void)rempauseLayer:(CALayer *)layer
  {
      CFTimeInterval pausedTime = [layer convertTime:CACurrentMediaTime() fromLayer:nil];
      layer.speed = 0.0;
      layer.timeOffset = pausedTime;
  }
  

• (void)remresumeLayer:(CALayer *)layer
  {
      CFTimeInterval pausedTime = [layer timeOffset];
      layer.speed = 1.0;
      layer.timeOffset = 0.0;
      layer.beginTime = 0.0;
      CFTimeInterval timeSincePause = [layer convertTime:CACurrentMediaTime() fromLayer:nil] - pausedTime;
      layer.beginTime = timeSincePause;
  }