iOS实现弹簧放大动画

效果图

实现代码

- (void)setUpContraints
{
    CGFloat topImageCentery = (SCREEN_HEIGHT - 370 * PLUS_SCALE) / 2;
    [self.topIconView mas_makeConstraints:^(MASConstraintMaker *make) {
        make.centerX.mas_equalTo(0);
        make.centerY.equalTo(self.view.mas_top).with.offset(topImageCentery);
    }];
    [self.view layoutIfNeeded];
}

- (void)topAnimation
{
    CASpringAnimation *springAnimation = [CASpringAnimation animationWithKeyPath:@"transform.scale"];
    springAnimation.mass = 1.5;
    springAnimation.stiffness = 400;
    springAnimation.damping = 20;
    springAnimation.initialVelocity = 0;
    springAnimation.duration = 1;
    springAnimation.fromValue = @0;
    springAnimation.toValue = @1;
    springAnimation.fillMode = kCAFillModeBoth;
    springAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
    [self.topIconView.layer addAnimation:springAnimation forKey:nil];
}