如何更改 Xcode 游乐场上的语言环境

Question

我想更改 Xcode Playground 上的语言环境以测试本地化。

我找到了这个解决方案，但它不适用于 Xcode 6.3.2 Playground： http://natashatherobot.com/locale-playground-swift/

Answer 1

哦，我找到解决办法了！

extension NSLocale {
    class func mono_currentLocale() -> NSLocale {
        return NSLocale(localeIdentifier: "fr")
    }
}
let original = class_getClassMethod(NSLocale.self, #selector(getter: NSLocale.currentLocale))
let swizzled = class_getClassMethod(NSLocale.self, #selector(NSLocale.mono_currentLocale))
method_exchangeImplementations(original, swizzled)

编辑：Swift 4.1 版本：

extension NSLocale {
    @objc class func mono_currentLocale() -> NSLocale {
        return NSLocale(localeIdentifier: "fr")
    }
}
let original = class_getClassMethod(NSLocale.self, #selector(getter: NSLocale.current))!
let swizzled = class_getClassMethod(NSLocale.self, #selector(NSLocale.mono_currentLocale))!
method_exchangeImplementations(original, swizzled)

Answer 2

XCode 13 / Swift 5

要更改 playground 中的当前语言环境，您可以创建 NSLocale 的扩展并覆盖 currentLocale:

extension NSLocale {
    @objc
    static let currentLocale = NSLocale(localeIdentifier: "en_GB") // Set a needed locale
}

let formatter = NumberFormatter()
formatter.numberStyle = .currency
let text = formatter.string(from: 12345.67 as NSNumber)!
print(text)

输出：

£12,345.67

NOTE: It also works with unit tests.