如何使这个复杂的动画重复和自动反转？有没有办法添加选项 UIViewAnimationOptionAutoreverse | UIViewAnimationOptionRepeat 到这个动画序列？
[UIView animateWithDuration:1.0f animations:^{
someView.frame = someFrame1;
} completion:^(BOOL finished) {
[UIView animateWithDuration:0.5f animations:^{
someView.frame = someFrame2;
} completion:nil];
}];
要从点 1 到 2 到 3 到 2 到 1 动画并重复，您可以animateKeyframesWithDuration在 iOS 7 及更高版本中使用：
someView.frame = frame1;
[UIView animateKeyframesWithDuration:2.0 delay:0.0 options:UIViewKeyframeAnimationOptionAutoreverse | UIViewKeyframeAnimationOptionRepeat animations:^{
[UIView addKeyframeWithRelativeStartTime:0.0 relativeDuration:0.5 animations:^{
someView.frame = frame2;
}];
[UIView addKeyframeWithRelativeStartTime:0.5 relativeDuration:0.5 animations:^{
someView.frame = frame3;
}];
} completion:nil];
如果使用自动布局，您可以动画约束常量的变化：
[UIView animateKeyframesWithDuration:2.0 delay:0.0 options:UIViewKeyframeAnimationOptionAutoreverse | UIViewKeyframeAnimationOptionRepeat animations:^{
[UIView addKeyframeWithRelativeStartTime:0.0 relativeDuration:0.5 animations:^{
topConstraint.constant = 200;
leftConstraint.constant = 200;
[self.view layoutIfNeeded];
}];
[UIView addKeyframeWithRelativeStartTime:0.5 relativeDuration:0.5 animations:^{
topConstraint.constant = 100;
leftConstraint.constant = 300;
[self.view layoutIfNeeded];
}];
} completion:nil];
或者，使用自动布局的方法是停用约束，然后您可以使用frame值或您拥有的东西进行动画处理。
在早期版本的 iOS 中，您可以使用CAKeyframeAnimation, 例如沿路径制作动画：
UIBezierPath *path = [UIBezierPath bezierPath];
[path moveToPoint:CGPointMake(100.0, 100.0)];
[path addLineToPoint:CGPointMake(200.0, 200.0)];
[path addLineToPoint:CGPointMake(100.0, 300.0)];
CAKeyframeAnimation *animatePosition = [CAKeyframeAnimation animationWithKeyPath:@"position"];
animatePosition.path = [path CGPath];
animatePosition.duration = 1.0;
animatePosition.autoreverses = YES;
animatePosition.repeatCount = HUGE_VALF;
[self.someView.layer addAnimation:animatePosition forKey:@"position"];
你可以用任何你想要的点来做到这一点。如果您想沿曲线路径（例如圆形或贝塞尔曲线）制作动画，这也是有用的技术。
要仅在两点之间设置动画，您可以使用animateWithDuration:delay:options:animations:completion:，例如：
[UIView animateWithDuration:0.5
delay:0.0
options:UIViewAnimationOptionAutoreverse | UIViewAnimationOptionRepeat | UIViewAnimationOptionCurveEaseInOut
animations:^{
// do whatever animation you want, e.g.,
someView.frame = someFrame1;
}
completion:NULL];
这将动画someView从起始帧someFrame1来回移动。
顺便说一句，与和UIViewAnimationOptionCurveEaseInOut一起使用会在动画反转和重复时为您提供更平滑的效果。UIViewAnimationOptionAutoreverseUIViewAnimationOptionRepeat
Swift 4 用于简单的摆动序列：
func animateWiggle() {
// Set animation props
let scaleDelta = CGFloat(0.10)
// Set transforms
let wiggleOutHorizontally = CGAffineTransform(scaleX: 1.0 + scaleDelta, y: 1.0)
let wiggleOutVertically = CGAffineTransform(scaleX: 1.0, y: 1.0 + scaleDelta)
// Run animation sequence
UIView.animateKeyframes(withDuration: 1.0, delay: 0.0, options: [.autoreverse, .repeat], animations: {
// Animate wiggle horizontally
UIView.addKeyframe(withRelativeStartTime: 0.0, relativeDuration: 0.5, animations: {
self.transform = wiggleOutHorizontally
})
// Animate wiggle vertically
UIView.addKeyframe(withRelativeStartTime: 0.5, relativeDuration: 0.5, animations: {
self.transform = wiggleOutVertically
})
},
completion: nil)
}
UIImageView *pin = [UIImageView new];
[pin setFrame:CGRectMake(115, 160, 30, 60)];
[pin setBackgroundColor:[UIColor redColor]];
[holderView addSubview:pin];
[UIView animateWithDuration:1.0 delay:0.0 options:UIViewAnimationOptionAutoreverse | UIViewAnimationOptionRepeat
animations:^{
// [pin setTransform:CGAffineTransformMakeTranslation(0, 20)];
[pin setFrame:CGRectMake(115, 200, 60, 100)];
}completion:^(BOOL finished){
}];