iphone - 弹跳按钮

Question

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Answer 1

检查 this blog描述了图标的弹跳效果。那应该引导你走向正确的方向。还有 check this lantean blog和 this cocoanetics blog.

这是他使用的代码，

+ (CAKeyframeAnimation*)dockBounceAnimationWithViewHeight:(CGFloat)viewHeight
{
    NSUInteger const kNumFactors    = 22;
    CGFloat const kFactorsPerSec    = 30.0f;
    CGFloat const kFactorsMaxValue  = 128.0f;
    CGFloat factors[kNumFactors]    = {0,  60, 83, 100, 114, 124, 128, 128, 124, 114, 100, 83, 60, 32, 0, 0, 18, 28, 32, 28, 18, 0};

    NSMutableArray* transforms = [NSMutableArray array];

    for(NSUInteger i = 0; i < kNumFactors; i++)
    {
        CGFloat positionOffset  = factors[i] / kFactorsMaxValue * viewHeight;
        CATransform3D transform = CATransform3DMakeTranslation(0.0f, -positionOffset, 0.0f);

        [transforms addObject:[NSValue valueWithCATransform3D:transform]];
    }

    CAKeyframeAnimation* animation = [CAKeyframeAnimation animationWithKeyPath:@"transform"];
    animation.repeatCount           = 1;
    animation.duration              = kNumFactors * 1.0f/kFactorsPerSec;
    animation.fillMode              = kCAFillModeForwards;
    animation.values                = transforms;
    animation.removedOnCompletion   = YES; // final stage is equal to starting stage
    animation.autoreverses          = NO;

    return animation;
}

- (void)bounce:(float)bounceFactor
{
    CGFloat midHeight = self.frame.size.height * bounceFactor;
    CAKeyframeAnimation* animation = [[self class] dockBounceAnimationWithViewHeight:midHeight];
    [self.layer addAnimation:animation forKey:@"bouncing"];
}