案例:
对loadingImageView, 需要不断做旋转动画,在某个时间点需要进行移动动画.
旋转动画如下:
- (void)rotateLoading{
[self.loadingImageView.layer removeAllAnimations];
CABasicAnimation *rotateAnim = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];
rotateAnim.fromValue = [NSNumber numberWithFloat:0];
rotateAnim.toValue = [NSNumber numberWithFloat:2*M_PI];
rotateAnim.duration = 0.6;
rotateAnim.repeatCount = MAXFLOAT;
[self.loadingImageView.layer addAnimation:rotateAnim forKey:@"rotate"];
}
移动动画如下:
[UIView animateWithDuration:0.5 animations:^{
self.loadingImageView.frame = self.originalFrame;
} completion:^(BOOL finished) {
if (finished) {
[self.loadingImageView.layer removeAllAnimations];
self.isLoading = NO;
}
}];
动画不正常.
分析:
原来在Frame属性中有如下说明:
@interface UIView(UIViewGeometry)
// animatable. do not use frame if view is transformed since it will not correctly reflect the actual location of the view. use bounds + center instead.
@property(nonatomic) CGRect frame;
即修改transform后, frame就不能正确地表示它的实际位置. 应该使用bounds + center 来代替.
解决:
改成对center做动画:
[UIView animateWithDuration:0.5 animations:^{
self.loadingImageView.center = self.originalCenter;
} completion:^(BOOL finished) {
if (finished) {
[self.loadingImageView.layer removeAllAnimations];
self.isLoading = NO;
}
}];
