how to change Application language on run time using Two Button in iphone SDK?

Question

i am building up a project in ios platform and want to use two language in this application and also want . the user can change the language on Runtime suppose we can ta

Answer 1

SWIFT 2.0 version We can do this on run time without restarting the app in Swift 2.0 as follows

Make a function within a class, lets say LanguageManager is the name of the class

class LanguageManager
{

    static let sharedInstance =  LanguageManager()

    //Make a function for Localization. Language Code is the one which we will be deciding on button click.
    func LocalizedLanguage(key:String,languageCode:String)->String{

        //Make sure you have Localizable bundles for specific languages.
        var path = NSBundle.mainBundle().pathForResource(languageCode, ofType: "lproj")

        //Check if the path is nil, make it as "" (empty path)
        path = (path != nil ? path:"")

        let languageBundle:NSBundle!

        if(NSFileManager.defaultManager().fileExistsAtPath(path!)){
            languageBundle = NSBundle(path: path!)
            return languageBundle!.localizedStringForKey(key, value: "", table: nil)
        }else{
            // If path not found, make English as default
            path = NSBundle.mainBundle().pathForResource("en", ofType: "lproj")
            languageBundle = NSBundle(path: path!)
           return languageBundle!.localizedStringForKey(key, value: "", table: nil)
        }
    }
}

How to Use this.
Now Assume you have two Languages for the application (English and Spanish)
English - en
Spanish - es

Suppose you have to place something for a label

//LOGIN_LABEL_KEY is the one that you will define in Localizable.strings for Login label text
 logInLabel.text = LanguageManager.sharedInstance.LocalizedLanguage("LOGIN_LABEL_KEY", languageCode: "es")

//This will use the Spanish version of the text. 
//"es" is the language code which I have hardcoded here. We can use a variable or some stored value in UserDefaults which will change on Button Click and will be passed in loginLabel

For more info on language codes see this link below
https://developer.apple.com/library/ios/documentation/MacOSX/Conceptual/BPInternational/LanguageandLocaleIDs/LanguageandLocaleIDs.html

or

http://www.ibabbleon.com/iOS-Language-Codes-ISO-639.html