iphone UIImageView旋转

Question

任何人都可以告诉我如何以圆周运动旋转图像

Answer 1

您可以按一定数量的弧度旋转视图,无论它是小于完整旋转还是完整旋转的多倍,而不必将旋转分割成碎片.作为示例,以下代码将每秒一次旋转视图达指定的秒数.您可以轻松地修改它以通过一定数量的旋转或一定数量的弧度来旋转视图.

- (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"];
}

Answer 2

如果您的意思是“如何使图像遵循圆形路径？”，那么伪代码将是：

image.x = circleCentre.x + cos(angle) * circleRadius;
image.y = circleCentre.y + sin(angle) * circleRadius;
angle += 5;