UIView无限360度旋转动画？ [英] UIView Infinite 360 degree rotation animation?

问题描述

我正在尝试旋转 UIImageView 360度，并在线查看了几个教程。如果没有 UIView 停止或跳到新位置，我就无法使用它们。

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.

• 我怎样才能实现这个目标？

我尝试过的最新事情是：

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!");
                 }];

但是如果我使用2 * pi，它根本不会移动（因为它是相同的位置）。如果我尝试做pi（180度），它可以工作，但是如果我再次调用该方法，它会向后旋转。

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.

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!");
                 }];

也不起作用。它会转到 180 度，暂停一会儿，然后在重新开始之前重新设置回 0 度。

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

推荐答案

找到一个方法（我修改了一下），对我来说非常合适： iphone UIImageView旋转

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"];
}

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