iphone的UIImageView旋轉

Question

誰能告訴我如何在圓周運動

Answer 1

如果你的意思是，旋轉圖像？「你怎麼做的圖像追隨圓形路徑」，那麼僞是：

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

Answer 2

This question要求同樣的事情，儘管換言之。在這個問題中的答案以及this question應該提供一種方法來爲UIView（UIImageView僅僅是它的一個子類）創建一個關於360度或更多中心的動畫。

Answer 3

無論是小於完整旋轉還是多次旋轉，都可以將視圖旋轉一定數量的弧度，而無需將旋轉分割成幾部分。作爲一個例子，下面的代碼會在一個指定的秒數內旋轉一個視圖，每秒一次。您可以輕鬆修改它以旋轉一定數量的旋轉視圖，或旋轉一定數量的弧度。

- (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"]; 
} 

Answer 4

基於mahboudz的回答，您可以將其設置設定爲無限旋轉：
rotationAnimation.repeatCount = HUGE_VALF;

Answer 5

創建動畫

- (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; 
} 

將它添加到一個視圖

CABasicAnimation *animation = [self spinAnimationWithDuration:1.0 clockwise:YES repeat:YES]; 
[self.spinningView.layer addAnimation:animation forKey:@"rotationAnimation"]; 

這個答案如何不同來自@ mahboudz的回答？如果大多數函數都返回對象，而不是僅僅操縱一些對象，那麼您將擁有更簡潔的代碼。