我试图旋转一个UIImageView 360度,并在网上看了几个教程。我不能让它们都工作,UIView要么停止,要么跳转到一个新位置。
我怎样才能做到这一点呢?
我最近尝试的是:
[UIView animateWithDuration:1.0
delay:0.0
options:0
animations:^{
imageToMove.transform = CGAffineTransformMakeRotation(M_PI);
}
completion:^(BOOL finished){
NSLog(@"Done!");
}];
但如果我使用2*pi,它根本不会移动(因为它是相同的位置)。如果我尝试只做(180度),它可以工作,但如果我再次调用这个方法,它会向后旋转。
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!");
}];
也不管用。它会转到180度,暂停一秒钟,然后在重新开始之前重置回0度。
我已经开发了一个闪亮的动画框架,可以节省你的时间!
使用它可以很容易地创建这个动画:
private var endlessRotater: EndlessAnimator!
override func viewDidAppear(animated: Bool)
{
super.viewDidAppear(animated)
let rotationAnimation = AdditiveRotateAnimator(M_PI).to(targetView).duration(2.0).baseAnimation(.CurveLinear)
endlessRotater = EndlessAnimator(rotationAnimation)
endlessRotater.animate()
}
要停止这个动画,只需将nil设置为endlessRotater。
如果你感兴趣,请看看:https://github.com/hip4yes/Animatics
我认为你最好添加一个UIVIew Category:
#import <QuartzCore/QuartzCore.h>
#import "UIView+Rotate.h"
实现UIView(旋转)
(void)remrotate360WithDuration:(CGFloat)duration repeatCount: (float)repeatCount
{
CABasicAnimation *fullRotation;
fullRotation = [CABasicAnimation animationWithKeyPath:@"transform.rotation"];
fullRotation.fromValue = [NSNumber numberWithFloat:0];
fullRotation.toValue = [NSNumber numberWithFloat:(2*M_PI)];
// fullRotation.toValue = [NSNumber numberWithFloat:-(2*M_PI)]; // added this minus sign as i want to rotate it to anticlockwise
fullRotation.duration = duration;
fullRotation.speed = 2.0f; // Changed rotation speed
if (repeatCount == 0)
fullRotation.repeatCount = MAXFLOAT;
else
fullRotation.repeatCount = repeatCount;
[self.layer addAnimation:fullRotation forKey:@"360"];
}
不使用此方法:)
(void)remstopAllAnimations
{
[self.layer removeAllAnimations];
};
(void)rempauseAnimations
{
[self rempauseLayer:self.layer];
}
(void)remresumeAnimations
{
[self remresumeLayer:self.layer];
}
(void)rempauseLayer:(CALayer *)layer
{
CFTimeInterval pausedTime = [layer convertTime:CACurrentMediaTime() fromLayer:nil];
layer.speed = 0.0;
layer.timeOffset = pausedTime;
}
(void)remresumeLayer:(CALayer *)layer
{
CFTimeInterval pausedTime = [layer timeOffset];
layer.speed = 1.0;
layer.timeOffset = 0.0;
layer.beginTime = 0.0;
CFTimeInterval timeSincePause = [layer convertTime:CACurrentMediaTime() fromLayer:nil] - pausedTime;
layer.beginTime = timeSincePause;
}
我在这个库中找到了很好的代码,
下面是它的代码,我做了一些小的改变,根据我的速度需要:)
UIImageView + Rotate.h
#import <Foundation/Foundation.h>
@interface UIImageView (Rotate)
- (void)rotate360WithDuration:(CGFloat)duration repeatCount:(float)repeatCount;
- (void)pauseAnimations;
- (void)resumeAnimations;
- (void)stopAllAnimations;
@end
UIImageView + Rotate.m
#import <QuartzCore/QuartzCore.h>
#import "UIImageView+Rotate.h"
@implementation UIImageView (Rotate)
- (void)rotate360WithDuration:(CGFloat)duration repeatCount:(float)repeatCount
{
CABasicAnimation *fullRotation;
fullRotation = [CABasicAnimation animationWithKeyPath:@"transform.rotation"];
fullRotation.fromValue = [NSNumber numberWithFloat:0];
//fullRotation.toValue = [NSNumber numberWithFloat:(2*M_PI)];
fullRotation.toValue = [NSNumber numberWithFloat:-(2*M_PI)]; // added this minus sign as i want to rotate it to anticlockwise
fullRotation.duration = duration;
fullRotation.speed = 2.0f; // Changed rotation speed
if (repeatCount == 0)
fullRotation.repeatCount = MAXFLOAT;
else
fullRotation.repeatCount = repeatCount;
[self.layer addAnimation:fullRotation forKey:@"360"];
}
//Not using this methods :)
- (void)stopAllAnimations
{
[self.layer removeAllAnimations];
};
- (void)pauseAnimations
{
[self pauseLayer:self.layer];
}
- (void)resumeAnimations
{
[self resumeLayer:self.layer];
}
- (void)pauseLayer:(CALayer *)layer
{
CFTimeInterval pausedTime = [layer convertTime:CACurrentMediaTime() fromLayer:nil];
layer.speed = 0.0;
layer.timeOffset = pausedTime;
}
- (void)resumeLayer:(CALayer *)layer
{
CFTimeInterval pausedTime = [layer timeOffset];
layer.speed = 1.0;
layer.timeOffset = 0.0;
layer.beginTime = 0.0;
CFTimeInterval timeSincePause = [layer convertTime:CACurrentMediaTime() fromLayer:nil] - pausedTime;
layer.beginTime = timeSincePause;
}
@end
我的贡献与一个快速扩展从检查解决方案:
斯威夫特4.0
extension UIView{
func rotate() {
let rotation : CABasicAnimation = CABasicAnimation(keyPath: "transform.rotation.z")
rotation.toValue = NSNumber(value: Double.pi * 2)
rotation.duration = 1
rotation.isCumulative = true
rotation.repeatCount = Float.greatestFiniteMagnitude
self.layer.add(rotation, forKey: "rotationAnimation")
}
}
弃用:
extension UIView{
func rotate() {
let rotation : CABasicAnimation = CABasicAnimation(keyPath: "transform.rotation.z")
rotation.toValue = NSNumber(double: M_PI * 2)
rotation.duration = 1
rotation.cumulative = true
rotation.repeatCount = FLT_MAX
self.layer.addAnimation(rotation, forKey: "rotationAnimation")
}
}
Nate上面的答案是理想的停止和开始动画,并提供了一个更好的控制。我很好奇为什么你的没用,而他的有用。我想在这里分享我的发现和一个更简单的代码版本,它可以使UIView连续动画而不停顿。
这是我用的代码,
- (void)rotateImageView
{
[UIView animateWithDuration:1 delay:0 options:UIViewAnimationOptionCurveLinear animations:^{
[self.imageView setTransform:CGAffineTransformRotate(self.imageView.transform, M_PI_2)];
}completion:^(BOOL finished){
if (finished) {
[self rotateImageView];
}
}];
}
我使用“CGAffineTransformRotate”而不是“CGAffineTransformMakeRotation”,因为前者返回的结果是随着动画的进行而保存的。这将防止在动画期间视图的跳跃或重置。
另一件事是不要使用'UIViewAnimationOptionRepeat'因为在动画的结尾,在它开始重复之前,它会重置变换,使视图跳回它的原始位置。不是重复,而是递归,这样转换就永远不会重置为原始值,因为动画块实际上永远不会结束。
最后一件事是,你必须以90度(M_PI / 2)的步伐转换视图,而不是360度或180度(2*M_PI或M_PI)。因为变换是正弦和余弦值的矩阵乘法。
t' = [ cos(angle) sin(angle) -sin(angle) cos(angle) 0 0 ] * t
所以,假设你使用180度变换,cos(180)产生-1,使得视图每次都在相反的方向变换(如果你把变换的弧度值改为M_PI, Note-Nate的答案也会有这个问题)。360度转换只是要求视图保持在原来的位置,因此你根本看不到任何旋转。