是否支持NSDirectionalEdgeInsets用于UIButton的contenEdgeInsets？

Question

我想对NSDirectionalEdgeInsets的{​​{3}}和UIButton使用titleEdgeInsets。有可能吗？

背景

出于本地化的目的，在设置组件的插图时，可能需要iOS应用程序同时适应从左到右和从右到左两种语言。

Apple在iOS11上引入了contentEdgeInsets，不幸的是，此方法仅应用于NSDirectionalEdgeInsets之类的少数属性，弃用了directionalLayoutMargins所用的UIEdgeInsets。

NSDirectionalEdgeInsets使用前导和跟踪修饰符代替左和右来遵循界面布局方向由其对应的UIEdgeInsets使用。

当前不当解决方案

为每个按钮/视图使用每个修改后的UIEdgeInsets属性使用以下代码非常麻烦，并且在进行更改时容易出错：

let isRTL: UIUserInterfaceLayoutDirection = // logic to determine language direction 

if isRTL == .leftToRight {
    nextButton.contentEdgeInsets = UIEdgeInsets(top: 0, left: 10, bottom: 0, right: 0)
} else {
    nextButton.contentEdgeInsets = UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 10)
}

Answer 1

解决方案

import UIKit

extension UIView {
    // Returns `UIEdgeInsets` set using `leading` and `trailing` modifiers adaptive to the language direction
    func getDirectionalUIEdgeInsets(top: CGFloat, leading: CGFloat, bottom: CGFloat, trailing: CGFloat) -> UIEdgeInsets {
        // NOTE: this wil be deprecated when Apple use `NSDirectioanlEdgeInsets` (https://developer.apple.com/documentation/uikit/nsdirectionaledgeinsets) for your insets property instead of `UIEdgeInsets`

        if self.userInterfaceLayoutDirection == .leftToRight {
            return UIEdgeInsets(top: top, left: leading, bottom: bottom, right: trailing)
        } else {
            return UIEdgeInsets(top: top, left: trailing, bottom: bottom, right: leading)
        }
    }

    /// Returns text and UI direction based on current view settings
    var userInterfaceLayoutDirection: UIUserInterfaceLayoutDirection
    {
        if #available(iOS 9.0, *) {
            return UIView.userInterfaceLayoutDirection(for: self.semanticContentAttribute)
        } else {
            return UIApplication.shared.userInterfaceLayoutDirection
        }
    }
}

用法

nextButton.contentEdgeInsets = nextButton.getDirectionalUIEdgeInsets(top: 0, leading: 10, bottom: 0, trailing: 0)

我在Stackoverflow上寻找答案，但一无所获。因此，我在分享我的答案。

信用

感谢 David Rysanek 的userInterfaceLayoutDirection this Stackoverflow answer。