有人能告诉我如何使图像以圆形运动旋转吗?
您可以旋转视图,旋转的角度可以少于一整个旋转或多个完整旋转的倍数,而无需将旋转拆分成几部分。例如,以下代码将使视图在指定秒数内每秒旋转一次。您可以轻松修改它以使视图旋转特定数量的旋转或某些弧度。
- (void) runSpinAnimationWithDuration:(CGFloat) duration;
{
CABasicAnimation* rotationAnimation;
rotationAnimation = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];
rotationAnimation.toValue = [NSNumber numberWithFloat: M_PI * 2.0 /* full rotation*/ * rotations * duration ];
rotationAnimation.duration = duration;
rotationAnimation.cumulative = YES;
rotationAnimation.repeatCount = 1.0;
rotationAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
[myView.layer addAnimation:rotationAnimation forKey:@"rotationAnimation"];
}
根据mahboudz的回答,您可以将其设置为无限旋转,方法如下:rotationAnimation.repeatCount = HUGE_VALF;
image.x = circleCentre.x + cos(angle) * circleRadius;
image.y = circleCentre.y + sin(angle) * circleRadius;
angle += 5;
- (CABasicAnimation *)spinAnimationWithDuration:(CGFloat)duration clockwise:(BOOL)clockwise repeat:(BOOL)repeats
{
CABasicAnimation *anim = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];
anim.toValue = clockwise ? @(M_PI * 2.0) : @(M_PI * -2.0);
anim.duration = duration;
anim.cumulative = YES;
anim.repeatCount = repeats ? CGFLOAT_MAX : 0;
return anim;
}
CABasicAnimation *animation = [self spinAnimationWithDuration:1.0 clockwise:YES repeat:YES];
[self.spinningView.layer addAnimation:animation forKey:@"rotationAnimation"];