iOS: How to change app language programmatically WITHOUT restarting the app?

Question

When I change the app used language independently on the device language it doesn't take effect until I close the app and restart it. How to not require app to be restarted for loading all nib files and .strings files again depending on the selected language?

I use this to change language at runtime:

NSArray* languages = [NSArray arrayWithObjects:@"ar", @"en", nil];  [[NSUserDefaults standardUserDefaults] setObject:languages forKey:@"AppleLanguages"]; 

Answer 1

This works for me : Swift 4 :

Create a file named BundleExtension.swift and add the following code to it -

var bundleKey: UInt8 = 0  class AnyLanguageBundle: Bundle {  override func localizedString(forKey key: String,                               value: String?,                               table tableName: String?) -> String {      guard let path = objc_getAssociatedObject(self, &bundleKey) as? String,         let bundle = Bundle(path: path) else {              return super.localizedString(forKey: key, value: value, table: tableName)     }      return bundle.localizedString(forKey: key, value: value, table: tableName)   } }  extension Bundle {  class func setLanguage(_ language: String) {      defer {          object_setClass(Bundle.main, AnyLanguageBundle.self)     }      objc_setAssociatedObject(Bundle.main, &bundleKey,    Bundle.main.path(forResource: language, ofType: "lproj"), .OBJC_ASSOCIATION_RETAIN_NONATOMIC)   } } 

Now whenever you need to change the language call this method :

func languageButtonAction() {     // This is done so that network calls now have the Accept-Language as "hi" (Using Alamofire) Check if you can remove these     UserDefaults.standard.set(["hi"], forKey: "AppleLanguages")     UserDefaults.standard.synchronize()      // Update the language by swaping bundle     Bundle.setLanguage("hi")      // Done to reintantiate the storyboards instantly     let storyboard = UIStoryboard.init(name: "Main", bundle: nil)     UIApplication.shared.keyWindow?.rootViewController = storyboard.instantiateInitialViewController() }