Swift:获取特定类型的所有子视图并添加到数组中

Question

我在UIView中有一个自定义类按钮,我想将它添加到一个数组中,以便它们易于访问.有没有办法获取特定类的所有子视图并将其添加到Swift中的数组？

Answer 1

filter使用is运算符的函数可以过滤特定类的项.

let myViews = view.subviews.filter{$0 is MyButtonClass}

MyButtonClass 是要过滤的自定义类.

Answer 2

干得好

    extension UIView {

    /** This is the function to get subViews of a view of a particular type 
*/
    func subViews<T : UIView>(type : T.Type) -> [T]{
        var all = [T]()
        for view in self.subviews {
            if let aView = view as? T{
                all.append(aView)
            }
        }
        return all
    }


/** This is a function to get subViews of a particular type from view recursively. It would look recursively in all subviews and return back the subviews of the type T */
        func allSubViewsOf<T : UIView>(type : T.Type) -> [T]{
            var all = [T]()
            func getSubview(view: UIView) {
                if let aView = view as? T{
                all.append(aView)
                }
                guard view.subviews.count>0 else { return }
                view.subviews.forEach{ getSubview(view: $0) }
            }
            getSubview(view: self)
            return all
        }
    }

你可以这样称呼它

let allSubviews = view.allSubViewsOf(type: UIView.self)
let allLabels = view.allSubViewsOf(type: UILabel.self)

Answer 3

这里的许多答案都是不必要的冗长或不够笼统。以下是如何获取一个视图的所有子视图，在任何深度，属于任何所需的类：

extension UIView {
    func subviews<T:UIView>(ofType WhatType:T.Type) -> [T] {
        var result = self.subviews.compactMap {$0 as? T}
        for sub in self.subviews {
            result.append(contentsOf: sub.subviews(ofType:WhatType))
        }
        return result
    }
}

如何使用：

let arr = myView.subviews(ofType: MyButtonClass.self)

Answer 4

要递归地执行此操作(即获取所有子视图的视图),您可以使用此通用函数:

private func getSubviewsOf<T : UIView>(view:UIView) -> [T] {
    var subviews = [T]()

    for subview in view.subviews {
        subviews += getSubviewsOf(view: subview) as [T]

        if let subview = subview as? T {
            subviews.append(subview)
        }
    }

    return subviews
}

要获取视图层次结构中的所有UILabel,只需执行以下操作:

let allLabels : [UILabel] = getSubviewsOf(view: theView)

Answer 5

我现在无法测试它,但这应该适用于Swift 2:

view.subviews.flatMap{ $0 as? YourView }

返回一个数组 YourView

这是一个经过测试的典型示例,用于计算:

countDots = allDots!.view.subviews.flatMap{$0 as? Dot}.count

Answer 6

如果您想更新/访问这些特定的子视图,请使用此方法,

for (index,button) in (view.subviews.filter{$0 is UIButton}).enumerated(){
    button.isHidden = false
}

Answer 7

在Swift 4.1中，您可以使用新的compactMap（现在不再使用flatMap）：https : //developer.apple.com/documentation/swift/sequence/2950916-compactmap （请参阅内部示例）

就您而言，您可以使用：

let buttons:[UIButton] = stackView.subviews.compactMap{ $0 as? UIButton }

您可以使用map对所有按钮执行操作：

let _ = stackView.subviews.compactMap{ $0 as? UIButton }.map { $0.isSelected = false }