动画旋转 UIImageView答案

【问题标题】：Animate Rotating UIImageView动画旋转 UIImageView
【发布时间】：2010-08-27 19:46:50
【问题描述】：

我想将UIImageView 向左/向右旋转大约 10 度，但动画很流畅，而不是我看到的突然转弯：

player.transform = CGAffineTransformMakeRotation(angle)

【问题讨论】：

标签： iphone animation uiimageview rotation

【解决方案1】：

[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:0.25]; // Set how long your animation goes for
[UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];

player.transform = CGAffineTransformMakeRotation(angle); // if angle is in radians

// if you want to use degrees instead of radians add the following above your @implementation
// #define degreesToRadians(x)(x * M_PI / 180)
// and change the above code to: player.transform = CGAffineTransformMakeRotation(degreesToRadians(angle));

[UIView commitAnimations];

// The rotation code above will rotate your object to the angle and not rotate beyond that.
// If you want to rotate the object again but continue from the current angle, use this instead:
// player.transform = CGAffineTransformRotate(player.transform, degreesToRadians(angle));

【讨论】：

【解决方案2】：

我使用一些这样的代码来实现类似的效果（虽然我将它旋转了 360 度）：

CABasicAnimation *rotate;
rotate = [CABasicAnimation animationWithKeyPath:@"transform.rotation"];
rotate.fromValue = [NSNumber numberWithFloat:0];
rotate.toValue = [NSNumber numberWithFloat:deg2rad(10)];
rotate.duration = 0.25;
rotate.repeatCount = 1;
[self.view.layer addAnimation:rotate forKey:@"10"];

我使用与此非常相似的代码来旋转图像视图。

【讨论】：

旋转角度是否需要使用弧度值？我第一次使用它，说没有声明 deg2rad，这是什么？也没有声明 CABasicAnimation。
是的，你需要弧度值； deg2rad 只是将 10 度转换为弧度的占位符。

【解决方案3】：

转换为 Swift 3/4：

let animation = CABasicAnimation(keyPath: "transform.rotation")
animation.fromValue = 0
animation.toValue =  Double.pi * 2.0
animation.duration = 2
animation.repeatCount = .infinity
animation.isRemovedOnCompletion = false

imageView.layer.add(animation, forKey: "spin")

【讨论】：

【解决方案4】：

我有一些代码可以旋转 360 度：

  - (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: rotations * 2.0 /* full rotation*/ * rotations * duration ];
    rotationAnimation.duration = duration;
    rotationAnimation.cumulative = YES;
    rotationAnimation.repeatCount = repeat;
    [view.layer addAnimation:rotationAnimation forKey:@"rotationAnimation"];
}

叫它：[self runSpinAnimationOnView:imgView duration:0.1 rotations:M_PI_4 repeat:10];

并且动画会一次又一次地旋转一些度数：

    - (void)rotateImage:(UIImageView *)image duration:(NSTimeInterval)duration delay:(NSTimeInterval)delay
              curve:(int)curve rotations:(CGFloat)rotations
{
    [UIView animateWithDuration:duration
                          delay:delay
                        options:0
                     animations:^{
                         [UIView setAnimationCurve:curve];
                         image.transform = CGAffineTransformMakeRotation(rotations);

                     }
                     completion:^(BOOL finished){
                         [self rotateImage2:image duration:duration delay:delay curve:curve rotations:rotations];
                         ;
                     }];
    [UIView commitAnimations];

}
- (void)rotateImage2:(UIImageView *)image duration:(NSTimeInterval)duration delay:(NSTimeInterval)delay
               curve:(int)curve rotations:(CGFloat)rotations
{
    [UIView animateWithDuration:duration
                          delay:delay
                        options:0
                     animations:^{
                         [UIView setAnimationCurve:curve];
                         image.transform = CGAffineTransformMakeRotation(-rotations);
                     }
                     completion:^(BOOL finished){
                         [self rotateImage:image duration:duration delay:delay curve:curve rotations:rotations];
                         ;
                     }];
    [UIView commitAnimations];

}

如果您想将 uiimageview 向左/向右旋转大约 10 度致电：[self rotateImage:imgView duration:0.7 delay:0.0 curve:UIViewAnimationCurveEaseIn rotations:(M_PI/18)]; 类似，有所下降

【讨论】：

【解决方案5】：

现代的Swift 解决方案，使用NSTimer 和CGAffineTransformMakeRotation：

class Rotation: UIViewController {
    var timer = NSTimer()
    var rotAngle: CGFloat = 0.0

    @IBOutlet weak var rotationImage: UIImageView!

    override func viewDidLoad() {
      super.viewDidLoad()
      activateTimer()
    }

    func activateTimer() {
      //(1)
      timer = NSTimer.scheduledTimerWithTimeInterval(1.0, target:self, selector:#selector(Rotation.updateCounter), userInfo: nil, repeats: true) 
    }

    func updateCounter() {
      //(2)
      var rotateLeft: Bool = true
      if rotateLeft {
        rotAngle -= 30.0
      } else {
        rotAngle += 30.0
      }
      //(3)
      UIView.animateWithDuration(2.0, animations: {
        self.rotationImage.transform = CGAffineTransformMakeRotation((self.rotAngle * CGFloat(M_PI)) / 180.0)
      })
    }
}

注意事项：

连接插座UIImageView
使用 (1) 计时器速度、(2) 动画速度和 (3) 旋转角度来获得所需的结果。这组变量对我有用。

【讨论】：