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。


当前回答

对于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");
}

其他回答

这对我很管用:

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

霉霉4更新了David Rysanek的精彩回答:

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")

        }   

    }
}
import UIKit

class RotatingImageView: UIImageView, CAAnimationDelegate {
    
    private let rotationAnimationKey = "rotationAnimationKey"

    private var shouldStopRotating = false
    
    func startRotating(witFullRotationDuration duration: Double = 0.5, halfRotation: Bool = true) {
        
        shouldStopRotating = false
        if layer.animation(forKey: rotationAnimationKey) == nil {
        
            let rotationAnimation = CABasicAnimation(keyPath: "transform.rotation")
            rotationAnimation.fromValue = 0.0
            rotationAnimation.toValue = halfRotation ? Float.pi : Float.pi * 2
            rotationAnimation.duration = duration
            rotationAnimation.repeatCount = 1
            rotationAnimation.delegate = self
            layer.add(rotationAnimation, forKey: rotationAnimationKey)
        
        }
        
    }

    func stopRotating(immediately: Bool = false) {
        if immediately {
            if layer.animation(forKey: rotationAnimationKey) != nil {
                layer.removeAnimation(forKey: rotationAnimationKey)
            }
        } else {
            shouldStopRotating = true
        }
    }
    
    func animationDidStop(_ anim: CAAnimation, finished flag: Bool) {
    
        if !shouldStopRotating {
            startRotating(witFullRotationDuration: anim.duration)
        } else {
            if layer.animation(forKey: rotationAnimationKey) != nil {
                layer.removeAnimation(forKey: rotationAnimationKey)
            }
        }
        
    }
    
}

我的贡献与一个快速扩展从检查解决方案:

斯威夫特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")
    }
}

弃用:

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")
    }
}

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()
    }
}