总结一套swift版本的APP内切换国际化语言

自己写一个工具类DAConfig；

一个Bundle的子类NSBundleEx；

一个Bundle的扩展协议；

class DAConfig: NSObject {

static let UWUserLanguageKey = "UWUserLanguageKey"         

class func setUserLanguage(userLanguage:String){        

if userLanguage.count == 0 {            

DAConfig.resetSystemLanguage()            

return;        

}        

UserDefaults.standard.set(userLanguage, forKey: DAConfig.UWUserLanguageKey)        UserDefaults.standard.set([userLanguage], forKey: "AppleLanguages")         UserDefaults.standard.synchronize()    

}         

class func getUserLanguage() -> String{        

Bundle.main.onLanguage()        

return ( UserDefaults.standard.object(forKey: DAConfig.UWUserLanguageKey) ?? NSLocale.preferredLanguages.first!) as! String    

}         

class func resetSystemLanguage() {        

UserDefaults.standard.removeObject(forKey: DAConfig.UWUserLanguageKey)         UserDefaults.standard.set(nil, forKey: "AppleLanguages")         UserDefaults.standard.synchronize()    

}

}

class NSBundleEx: 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, NSBundleEx.self)    

}    

func onLanguage(){        

        Bundle.onLanguageDispatchOnce()    

}         

class func getLanguageBundel() -> Bundle? {

        let languageBundlePath =         Bundle.main.path(forResource:DAConfig.getUserLanguage(), ofType: "lproj")        

        guard languageBundlePath != nil else {

            return nil        

        }

        let languageBundle = Bundle.init(path: languageBundlePath!)

        guard languageBundle != nil else {

            return nil

        }

        return languageBundle!

       }

}

因为swift不允许重写load方法 所以我们用的是onLanguage(),需要在程序启动时调用它；

使用时如下：

if indexPath.row == 0 {

            DAConfig.setUserLanguage(userLanguage: "zh-Hans")

        }else{

            DAConfig.setUserLanguage(userLanguage: "en")

}