iOS之tabBar按钮动画效果

- (void)animationWithIndex:(NSInteger) index {
    NSMutableArray * tabbarbuttonArray = [NSMutableArray array];
    for (UIView *tabBarButton in self.tabBar.subviews) {
        if ([tabBarButton isKindOfClass:NSClassFromString(@"UITabBarButton")]) {
            [tabbarbuttonArray addObject:tabBarButton];
        }
    }
    CABasicAnimation*pulse = [CABasicAnimation animationWithKeyPath:@"transform.scale"];
    pulse.timingFunction= [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
    //动画持续时间
    pulse.duration = 0.15;
    //重复次数
    pulse.repeatCount= 2;
    //设定这个属性为 YES 时,在它到达目的地之后,动画的返回到开始的值,代替了直接跳转到开始的值，过渡平滑
    pulse.autoreverses= YES;
    //动画初始值
    pulse.fromValue= [NSNumber numberWithFloat:1.0];
    //动画到达值
    pulse.toValue= [NSNumber numberWithFloat:0.7];
    [[tabbarbuttonArray[index] layer] addAnimation:pulse forKey:nil];
}