ios - 动画在 Swift 中显示和隐藏 View

Question

我有这个功能:

func showwAndHideFilterMenu(category : Int) {

    if showFilterMenu == false{
        UIView.animate(withDuration: 0.6, delay: 0, options: .curveEaseInOut, animations: {
            self.filterView.isHidden = false
            self.showFilterMenu = true       
        }) { (isCompleted) in
        }

    } else {
        UIView.animate(withDuration: 0.6, delay: 0, options: .curveEaseInOut, animations: {
            self.filterView.isHidden = true
            self.self.showFilterMenu = false       
        }) { (isCompleted) in
        }
    }
}

我有一个显示和隐藏 View 的函数。我想添加一个动画来显示/隐藏这个 View 。怎么做？动画的方向将从上到下。

有人知道怎么做吗？

Answer 1

您需要操作 alpha 属性而不是 isHidden 属性来为 UIView 淡入淡出动画。

尝试以下操作:

func showAndHideFilterMenu(category : Int) {
    if showFilterMenu == false {
        self.filterView.alpha = 0.0
        self.filterView.isHidden = false
        self.showFilterMenu = true

        UIView.animate(withDuration: 0.6, 
                       animations: { [weak self] in
                        self?.filterView.alpha = 1.0
        })
    } else {
        UIView.animate(withDuration: 0.6,
                       animations: { [weak self] in
                        self?.filterView.alpha = 0.0
        }) { [weak self] _ in
            self?.filterView.isHidden = true
            self?.showFilterMenu = false
        }
    }
}