Question

我的设置如下：

UIView（1） - ＆gt; UIScrollview - ＆gt; UIStackview - ＆gt; UIViews（2） - ＆gt;的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函数中添加此内容时，它不会打印任何内容。我在这里做错了什么？

Answer 1

首先想到的解决方案：

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。

如果你想要一个更稳定的解决方案，你可以在任何深度的子视图上递归迭代，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 }

Answer 2

怎么样......

for view in stackView.subviews {
    for case let button as UIButton in view.subviews {
        print(button.title(for: .normal)) // Do something with button
    }
}

或

for case let button as UIButton in stackView.subviews.flatMap({ $0.subviews }) {
    print(button.title(for: .normal))  // Do something with button
}

或

for button in stackView.subviews.flatMap({ $0.subviews }).flatMap({ $0 as? UIButton }) {
    print(button.title(for: .normal))  // Do something with button
}

在UIView中通过UIButton循环

2 个答案: