iphone - 振动 UI 项目的最佳方式？

Question

我正在尝试振动/摇动一个 UI 元素，即一个控件，就好像它被敲击一样，并且正在共振。我可以使用核心动画将其垂直、水平或同时摇动一个像素:

CABasicAnimation* rotationXAnimation;
rotationXAnimation = [CABasicAnimation animationWithKeyPath:@"position.y"];
rotationXAnimation.fromValue = [NSNumber numberWithFloat: ((UIControl *) sender).center.y-1.0 ];
rotationXAnimation.toValue = [NSNumber numberWithFloat: ((UIControl *) sender).center.y+1.0 ];
rotationXAnimation.duration = 0.2;
rotationXAnimation.cumulative = NO; 
rotationXAnimation.repeatCount = 10.0; 
rotationXAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];

[((UIControl *) sender).layer addAnimation:rotationXAnimation forKey:@"upDownAnimation"];

或者我可以围绕 z 轴来回旋转一个小弧度(-M_PI * 0.02 和 M_PI * 0.02):

CABasicAnimation* rotationAnimation;
rotationAnimation = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];
rotationAnimation.fromValue = [NSNumber numberWithFloat: -M_PI * 0.02 ];
rotationAnimation.toValue = [NSNumber numberWithFloat: M_PI * 0.02 ];
rotationAnimation.duration = 0.2;
rotationAnimation.cumulative = NO;  
rotationAnimation.repeatCount = 10.0; 
rotationAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];

[((UIControl *) sender).layer addAnimation:rotationAnimation forKey:@"rotationAnimation"];

这些看起来都不那么令人愉快。有人有一些好的选择吗？我特别感谢尝试很酷的 keyPaths 想法。

谢谢!

更新:

下面我收缩和扩展控制的情况更好，但我仍在寻找其他想法。

CABasicAnimation* scaleAnimation;
scaleAnimation = [CABasicAnimation animationWithKeyPath:@"transform.scale"];
scaleAnimation.fromValue = [NSNumber numberWithFloat: 0.95 ];
scaleAnimation.toValue = [NSNumber numberWithFloat: +1.05 ];
scaleAnimation.duration = 0.1;
scaleAnimation.cumulative = NO; 
scaleAnimation.repeatCount = 10.0; 
scaleAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];

[((UIControl *) sender).layer addAnimation:scaleAnimation forKey:@"scaleAnimation"];

Answer 1

在用户输入错误后，我正在摇动我的输入 View 之一:

- (void)earthquake:(UIView*)itemView
{
    CGFloat t = 2.0;
    CGAffineTransform leftQuake  = CGAffineTransformTranslate(CGAffineTransformIdentity, t, -t);
    CGAffineTransform rightQuake = CGAffineTransformTranslate(CGAffineTransformIdentity, -t, t);

    itemView.transform = leftQuake;  // starting point

    [UIView beginAnimations:@"earthquake" context:itemView];
    [UIView setAnimationRepeatAutoreverses:YES]; // important
    [UIView setAnimationRepeatCount:4];
    [UIView setAnimationDuration:0.07];
    [UIView setAnimationDelegate:self];
    [UIView setAnimationDidStopSelector:@selector(earthquakeEnded:finished:context:)];

    itemView.transform = rightQuake; // end here & auto-reverse

    [UIView commitAnimations];
}

- (void)earthquakeEnded:(NSString *)animationID finished:(NSNumber *)finished context:(void *)context 
{
    if ([finished boolValue]) 
    {
        UIView* item = (UIView *)context;
        item.transform = CGAffineTransformIdentity;
    }
}

这看起来很自然，我从一些我不记得的互联网线程中获得了这段代码。