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

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")

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);
}];

我认为你最好添加一个UIVIew Category:

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

实现UIView(旋转)

(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"]; }

不使用此方法:)

(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; }

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)
            }
        }
        
    }
    
}

Nate上面的答案是理想的停止和开始动画,并提供了一个更好的控制。我很好奇为什么你的没用,而他的有用。我想在这里分享我的发现和一个更简单的代码版本,它可以使UIView连续动画而不停顿。

这是我用的代码,

- (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];
        }
    }];
}

我使用“CGAffineTransformRotate”而不是“CGAffineTransformMakeRotation”,因为前者返回的结果是随着动画的进行而保存的。这将防止在动画期间视图的跳跃或重置。

另一件事是不要使用'UIViewAnimationOptionRepeat'因为在动画的结尾,在它开始重复之前,它会重置变换,使视图跳回它的原始位置。不是重复,而是递归,这样转换就永远不会重置为原始值,因为动画块实际上永远不会结束。

最后一件事是,你必须以90度(M_PI / 2)的步伐转换视图,而不是360度或180度(2*M_PI或M_PI)。因为变换是正弦和余弦值的矩阵乘法。

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

所以,假设你使用180度变换,cos(180)产生-1,使得视图每次都在相反的方向变换(如果你把变换的弧度值改为M_PI, Note-Nate的答案也会有这个问题)。360度转换只是要求视图保持在原来的位置,因此你根本看不到任何旋转。

你也可以用UIView和block做同样类型的动画。下面是一个类扩展方法,它可以以任何角度旋转视图。

- (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();
    }
}