Question

我在执行旋转动画之前先执行UIImageView的旋转：

// rotate to the left by 90 degrees
someView.transform = CGAffineTransformMakeRotation((-0.5)*M_PI);

然后将视图上的旋转调整180度......但似乎它是从原始位置开始旋转图像，就像它最初没有旋转一样。

- (void)rotateIndicatorToAngle: (UIView *)view angle: (NSNumber *)angleInDegrees
{
    CALayer *layer = view.layer;
    CGFloat duration = 5.0;
    CGFloat radians = [self ConvertDegreesToRadians: [angleInDegrees floatValue]];
    CABasicAnimation* rotationAnimation;
    rotationAnimation = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];
    rotationAnimation.toValue = [NSNumber numberWithFloat: radians];
    rotationAnimation.duration = duration;
    rotationAnimation.cumulative = YES;
    rotationAnimation.repeatCount = 1.0;
    rotationAnimation.removedOnCompletion = NO;
    rotationAnimation.fillMode = kCAFillModeForwards;
    rotationAnimation.timingFunction = [CAMediaTimingFunction
functionWithName:kCAMediaTimingFunctionEaseOut];

[layer addAnimation: rotationAnimation forKey: @"rotationAnimation"];
}

是什么给出了？

Answer 1

rotationAnimation.cumulative = YES;

您是否尝试过使用rotationAnimation.additive = YES;而不是累积？

Answer 2

您可以使用UIView中的类方法轻松为视图设置动画：

[UIView beginAnimation: @"Rotate" context: nil];
[UIView setAnimationDuration: 5.0f];
[UIView setAnimationCurve: UIViewAnimationCurveEaseOut];

CGFloat radians = [self ConvertDegreesToRadians: [angleInDegrees floatValue]];
view.transform = CGAffineTransformMakeRotation(radians);

[UIView commitAnimation];

这就是我大部分时间都在使用的，不需要使用图层。

更新：我的意思是，我发现在这种情况下不使用图层更容易，对使用图层没有贬义价值。

在CABasicAnimation之前的CGAffineTransformMakeRotation

2 个答案: