CABasicAnimation在x轴上旋转视图

问题描述：

我需要在180度的x轴上旋转我的视图。旋转完成，但当它开始旋转时，它会折叠我的半视图。这是我所做的任何帮助的代码。CABasicAnimation在x轴上旋转视图

 CABasicAnimation* rotationAnimation; 
     rotationAnimation = [CABasicAnimation animationWithKeyPath:@"transform.rotation.x"]; 
     rotationAnimation.fromValue = [NSNumber numberWithFloat:0]; 
     rotationAnimation.toValue = [NSNumber numberWithFloat: M_PI * 2.0]; 
     rotationAnimation.duration = 2.0; 
     rotationAnimation.cumulative = YES; 
     rotationAnimation.repeatCount = 0; 
     [_view_topShowDate.layer addAnimation:rotationAnimation forKey:@"rotationAnimation"];

您可以发布折叠视图的图像吗？ – shallowThought

[使用CABasicAnimation多次旋转UIImageView]的可能重复（http://stackoverflow.com/questions/17426802/using-cabasicanimation-to-rotate-a-uiimageview-more-than-once） –

答

您必须在viewDidLoad或动画开始之前的某个位置设置定位点。默认情况下，它将anchorPoint作为（0.5,0.5），因此您可以看到来自中心的旋转。

_viewToRotate.layer.anchorPoint = CGPointMake(0.5, 1.0);

然后调用基本的动画方法。

了解更多关于http://ronnqvi.st/about-the-anchorpoint/

当你改变锚点，它移动层的位置。要重新定位它，请使用以下内容

-(void)setNewAnchorPoint:(CGPoint)anchorPoint forView:(UIView *)view 
{ 
    CGPoint newPoint = CGPointMake(view.bounds.size.width * anchorPoint.x, view.bounds.size.height * anchorPoint.y); 
    CGPoint oldPoint = CGPointMake(view.bounds.size.width * view.layer.anchorPoint.x, view.bounds.size.height * view.layer.anchorPoint.y); 

    newPoint = CGPointApplyAffineTransform(newPoint, view.transform); 
    oldPoint = CGPointApplyAffineTransform(oldPoint, view.transform); 

    CGPoint position = view.layer.position; 

    position.x -= oldPoint.x; 
    position.x += newPoint.x; 

    position.y -= oldPoint.y; 
    position.y += newPoint.y; 

    view.layer.position = position; 
    view.layer.anchorPoint = anchorPoint; 
}

CABasicAnimation在x轴上旋转视图

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