swift - 如何使用 Swift 在 UITabbar 第一个项目上添加自定义标签

Question

我的场景，我需要在 UITabbar 第一项中心位置添加一个自定义标签，因为基于标签中心位置，我将在其上应用圆形过渡起点。

我的代码如下

func animationController(forPresented presented: UIViewController, presenting: UIViewController, source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
        transition.transitionMode = .present
        transition.startingPoint = customLabel.center // here I need to get custom label center position 
        return transition
    }

func animationController(forDismissed dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
        transition.transitionMode = .dismiss
        transition.startingPoint =  customLabel.center
        return transition
    }

标签： swift