在UIView中通过UIButton循环

Question

我的设置如下:

UIView(1) - > UIScrollview - > UIStackview - > UIViews(2) - > UIButton

如何遍历UIStackview中所有UIViews(2)中的每个UIButton？我的UIView(1)中有更多按钮,所以我无法遍历整个Viewcontroller中的每个按钮.我试过了:

for view in self.stackview.subviews as [UIView] {
    if let btn = view as? UIButton {
        print("Worked")
    }
}
for view in self.scrollview.subviews as [UIView] {
    if let btn = view as? UIButton {
        print("Worked")
    }
}
for case let button as UIButton in self.scrollview.subviews {
    print("worked")
}
for case let button as UIButton in self.stackview.subviews {
    print("worked")
}

尝试在我的viewDidLoad函数中添加它时,它只是不打印任何东西.我在这做错了什么？

Answer 1

首先要考虑的解决方案:

let buttons = self.stackview.subviews // direct subviews of stack view
    .map { subview in subview.subviews } // second level subviews
    .joined() // join the second level subviews into one flat array
    .compactMap { $0 as? UIButton } // filter buttons

基本上你只是忘了跳到第二级.您只迭代第一级子视图.

如果您想要一个更稳定的解决方案,您可以在任何深度上递归迭代子视图,例如使用类别:

extension UIView {
    var allSubviews: [UIView] {
        return self.subviews + self.subviews.map { $0.allSubviews }.joined()
    }
}

然后

let buttons = self.stackview.allSubviews.compactMap { $0 as? UIButton }