顺时针旋转UIImageView

Question

这应该很简单,但我无法旋转UIImageView360度,永远重复.

[UIView animateWithDuration:0.5 delay:0 options:UIViewAnimationOptionAllowUserInteraction | UIViewAnimationOptionRepeat | UIViewAnimationOptionCurveLinear | UIViewAnimationOptionBeginFromCurrentState animations:^{
    self.reloadButton.imageView.transform = CGAffineTransformRotate(self.reloadButton.imageView.transform, -M_PI);
} completion:^(BOOL finished) {

}];

根据文档,我传递的角度的符号CGAffineTransformRotate确定旋转方向,但上面的代码逆时针旋转.与...相同M_PI.

以弧度表示的角度,此矩阵旋转坐标系轴.在iOS中,正值指定逆时针旋转,负值指定顺时针旋转.在Mac OS X中,正值指定顺时针旋转,负值指定逆时针旋转.

Answer 1

Christoph已经采用了正确的方式,但是有一种更好的方法可以让它保持旋转状态,而不会在动画代表每次结束时重新调整它.这是完全错误的.

只需将动画的repeatCount属性设置为HUGE_VALF.

CABasicAnimation* animation = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];
animation.fromValue = @0.0f;
animation.toValue = @(2*M_PI);
animation.duration = 0.5f;             // this might be too fast
animation.repeatCount = HUGE_VALF;     // HUGE_VALF is defined in math.h so import it
[self.reloadButton.imageView.layer addAnimation:animation forKey:@"rotation"];

如文档中所述,这将导致动画永远重复.