通過遞歸獲取指定view的所有子視圖.

1. 獲取View的子視圖

使用

    let subViewArr = view.getAllSubViews() // 獲取所有子視圖
    let imageViewArr = view.getSubView(name: "UIImageView") // 獲取指定類名的子視圖

實現(xiàn)

extension UIView {
    private static var getAllsubviews: [UIView] = []
    public func getSubView(name: String) -> [UIView] {
        let viewArr = viewArray(root: self)
        UIView.getAllsubviews = []
        return viewArr.filter {$0.className == name}
    }
    public func getAllSubViews() -> [UIView] {
        UIView.getAllsubviews = []
        return viewArray(root: self)
    }
    private func viewArray(root: UIView) -> [UIView] {
        for view in root.subviews {
            if view.isKind(of: UIView.self) {
                UIView.getAllsubviews.append(view)
            }
            _ = viewArray(root: view)
        }
        return UIView.getAllsubviews
    }
}

extension NSObject {
    var className: String {
        let name = type(of: self).description()
        if name.contains(".") {
            return name.components(separatedBy: ".")[1]
        } else {
            return name
        }
    }
}

2. 獲取UIAlertController的titleLabel和messageLabel

UIAlertController好用,但可自定義程度不高,例如我們想讓message文字左對齊,就需要獲取到messageLabel,但UIAlertController并沒有提供這個屬性.

我們就可以通過遞歸拿到alertTitleLabel和alertMessageLabel.

extension UIAlertController {
    public var alertTitleLabel: UILabel? {
        return self.view.getSubView(name: "UILabel").first as? UILabel
    }
    public var alertMessageLabel: UILabel? {
        return self.view.getSubView(name: "UILabel").last as? UILabel
    }
}

雖然通過這種方法可以拿到alertTitleLabel和alertMessageLabel.但沒法區(qū)分哪個是哪個,alertTitleLabel為默認(rèn)子控件的第一個label,如果title傳空,message傳值,alertTitleLabel和alertMessageLabel獲取到的都是message的label.

如果有更好的方法歡迎討論.

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