Come ruotare UIView, UIImageView o CALayer animati 360˚?

Question

Come si ruota UIView, UIImageView o CALayer animato a 360 gradi senza utilizzare OpenGL ES?

Answer 1

Presumibilmente si intende animare la rotazione di un UIImage intorno a 360 °? Nella mia esperienza, il modo per compiere una rotazione completa cerchio è a catena più animazioni insieme:

- (IBAction)rotate:(id)sender 
{ 
    [UIView beginAnimations:@"step1" context:NULL]; { 
     [UIView setAnimationDuration:1.0]; 
     [UIView setAnimationDidStopSelector:@selector(animationDidStop:finished:context:)]; 
     [UIView setAnimationDelegate:self]; 
    [imageView.transform = CGAffineTransformMakeRotation(120 * M_PI/180); 
    } [UIView commitAnimations]; 
} 

- (void)animationDidStop:(NSString *)animationID finished:(NSNumber *)finished context:(void *)context 
{ 
    if ([animationID isEqualToString:@"step1"]) { 
     [UIView beginAnimations:@"step2" context:NULL]; { 
     [UIView setAnimationDuration:1.0]; 
     [UIView setAnimationDidStopSelector:@selector(animationDidStop:finished:context:)]; 
     [UIView setAnimationDelegate:self]; 
     imageView.transform = CGAffineTransformMakeRotation(240 * M_PI/180); 
     } [UIView commitAnimations]; 
    } 
    else if ([animationID isEqualToString:@"step2"]) { 
     [UIView beginAnimations:@"step3" context:NULL]; { 
     [UIView setAnimationDuration:1.0]; 
     [UIView setAnimationDidStopSelector:@selector(animationDidStop:finished:context:)]; 
     [UIView setAnimationDelegate:self]; 
     imageView.transform = CGAffineTransformMakeRotation(0); 
     } [UIView commitAnimations]; 
    } 
} 

ho lasciato la curva (invece che lineare) al posto easeIn/easeOut, in modo da poter vedere le singole animazioni.

Answer 2

#import <QuartzCore/QuartzCore.h> 

CABasicAnimation *fullRotation; 
fullRotation = [CABasicAnimation animationWithKeyPath:@"transform.rotation"]; 
fullRotation.fromValue = @(0.0); 
fullRotation.toValue = @((360.0 * M_PI)/180.0); 
fullRotation.duration = 3.5f; 
fullRotation.repeatCount = MAXFLOAT; 

[view.layer addAnimation:fullRotation forKey:@"rotation-animation"]; 

Se si desidera cambiare il punto di ancoraggio a ruota attorno allora si può fare

CGRect frame = view.layer.frame; 
self.anchorPoint = CGPointMake(0.5, 0.5); // rotates around center 
self.frame = frame;