iOS 多国语言本地化与App内语言切换（Swift）

# Localizable.strings文件路径
localizableFile="${SRCROOT}/${PROJECT_NAME}/Support/en.lproj/Localizable.strings"
# 生成的swift文件路径（根据个人习惯修改）
localizedFile="${SRCROOT}/${PROJECT_NAME}/Source/Utils/LocalizedUtils.swift"
# 将localizable.strings中的文本转为swift格式的常量，存入一个临时文件
sed "s/^\"/  static var localized_/g" "${localizableFile}" | sed "s/\" = \"/: String { return \"/g" | sed "s/;$/.localized }/g" > "${localizedFile}.tmp"
# 先将localized作为计算属性输出到目标文件
echo -e "import Foundation\n\nextension String {\n  var localized: String { return NSLocalizedString(self, comment: self) }" > "${localizedFile}"
# 再将临时文件中的常量增量输出到目标文件
cat "${localizedFile}.tmp" >> "${localizedFile}"
# 最后增量输出一个"}"到目标文件，完成输出
echo -e "\n}" >> "${localizedFile}"
# 删除临时文件
rm "${localizedFile}.tmp"

enum Language : String {
    case english = "en"
    case chinese = "zh-Hans"
}
/**
 *  当调用onLanguage后替换掉mainBundle为当前语言的bundle
 */
class BundleEx: Bundle {
    override func localizedString(forKey key: String, value: String?, table tableName: String?) -> String {
        if let bundle = Bundle.getLanguageBundel() {
            return bundle.localizedString(forKey: key, value: value, table: tableName)
        }else {
            return super.localizedString(forKey: key, value: value, table: tableName)
        }
    }
}
extension Bundle {
    private static var onLanguageDispatchOnce: ()->Void = {
        //替换Bundle.main为自定义的BundleEx
        object_setClass(Bundle.main, BundleEx.self)
    }
    func onLanguage(){
        Bundle.onLanguageDispatchOnce()
    }
    class func getLanguageBundel() -> Bundle? {
        let languageBundlePath = Bundle.main.path(forResource: UserDefaults.standard[AppStatic.kCurrentLanguage] as? String, ofType: "lproj")
//        print("path = \(languageBundlePath)")
        guard languageBundlePath != nil else {
            return nil
        }
        let languageBundle = Bundle.init(path: languageBundlePath!)
        guard languageBundle != nil else {
            return nil
        }
        return languageBundle!
    }
}

    public subscript(key: String) -> Any? {
        get {
            return object(forKey: key)
        }
        set {
            set(newValue, forKey: key)
        }
    }

# Localizable.strings文件路径
localizableFile="${SRCROOT}/Base.lproj/Localizable.strings"
# 生成的swift文件路径（根据个人习惯修改）
localizedFile="${SRCROOT}/Public/LocalizedUtils.swift"
# 将localizable.strings中的文本转为swift格式的常量，存入一个临时文件
sed "s/^\"/  static var localized_/g" "${localizableFile}" | sed "s/\" = \"/: String { return \"/g" | sed "s/;$/.localized }/g" > "${localizedFile}.tmp"
# 先将localized作为计算属性输出到目标文件
echo -e "import Foundation\n\nextension String {\n  var localized: String { Bundle.main.onLanguage() \n return NSLocalizedString(self, comment: self) }" > "${localizedFile}"
# 再将临时文件中的常量增量输出到目标文件
cat "${localizedFile}.tmp" >> "${localizedFile}"
# 最后增量输出一个"}"到目标文件，完成输出
echo -e "\n}" >> "${localizedFile}"
# 删除临时文件
rm "${localizedFile}.tmp"

    func chooseLanguage() {
        DispatchQueue.global().async {
            let sheet = UIAlertController.init(title: String.localized_Choose_Language, message: nil, preferredStyle: .actionSheet)
            sheet.addAction(UIAlertAction.init(title: String.localized_English, style: .default, handler: { (action) in
                UserDefaults.standard[AppStatic.kCurrentLanguage] = Language.english.rawValue
                UIApplication.shared.keyWindow?.rootViewController = RedbotTabBar()
                UIApplication.shared.keyWindow?.alpha = 0
                AlertHelper.showHudWithMessage(message: "Setting Language...")
                DispatchQueue.main.asyncAfter(deadline: DispatchTime.now()+1, execute: {
                    UIView.animate(withDuration: 1, animations: {UIApplication.shared.keyWindow?.alpha = 1})
                    AlertHelper.hideHudMessage()
                })
            }))
            sheet.addAction(UIAlertAction.init(title: String.localized_Chinese, style: .default, handler: { (action) in
                UserDefaults.standard[AppStatic.kCurrentLanguage] = Language.chinese.rawValue
                UIApplication.shared.keyWindow?.rootViewController = RedbotTabBar()
                UIApplication.shared.keyWindow?.alpha = 0
                AlertHelper.showHudWithMessage(message: "Setting Language...")
                DispatchQueue.main.asyncAfter(deadline: DispatchTime.now()+1, execute: {
                    UIView.animate(withDuration: 1, animations: {UIApplication.shared.keyWindow?.alpha = 1})
                    AlertHelper.hideHudMessage()
                })
            }))
            sheet.addAction(UIAlertAction.init(title: String.localized_Cancel, style: .cancel, handler: nil))
            self.present(sheet, animated: true, completion: nil)
        }
    }