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

Answer 2

You have to use localization for this . Just store the key and value in side localizable.string and load the appropriate .string file as per your requirement . You can refer following tutorial for this : http://www.raywenderlich.com/2876/how-to-localize-an-iphone-app-tutorial

Answer 3

Here is demo tutorial

https://github.com/object2dot0/Advance-Localization-in-ios-apps

Just remove

 [self dealloc];

from

 -(IBAction) languageSelection:(id)sender

so it wont be crash!!! enjoy!

Answer 4

I came up with a solution that allows you to use NSLocalizedString. I create a category of NSBundle call NSBundle+RunTimeLanguage. The interface is like this.

// NSBundle+RunTimeLanguage.h
#import <Foundation/Foundation.h>
@interface NSBundle (RunTimeLanguage)
#define NSLocalizedString(key, comment) [[NSBundle mainBundle] runTimeLocalizedStringForKey:(key) value:@"" table:nil]
- (NSString *)runTimeLocalizedStringForKey:(NSString *)key value:(NSString *)value table:(NSString *)tableName;
@end

The implementation is like this.

// NSBundle+RunTimeLanguage.m
#import "NSBundle+RunTimeLanguage.h"
#import "AppDelegate.h"

@implementation NSBundle (RunTimeLanguage)

- (NSString *)runTimeLocalizedStringForKey:(NSString *)key value:(NSString *)value table:(NSString *)tableName
{
    AppDelegate *appDelegate = (AppDelegate *)[UIApplication sharedApplication].delegate;
    NSString *path= [[NSBundle mainBundle] pathForResource:[appDelegate languageCode] ofType:@"lproj"];
    NSBundle *languageBundle = [NSBundle bundleWithPath:path];
    NSString *localizedString=[languageBundle localizedStringForKey:key value:key table:nil];
    return localizedString;
}
@end

Than just add import NSBundle+RunTimeLanguage.h into the files that use NSLocalizedString.

As you can see I store my languageCode in a property of AppDelegate. This could be stored anywhere you'd like.

This only thing I don't like about it is a Warning that NSLocalizedString marco redefined. Perhaps someone could help me fix this part.

Answer 5

Assuming that you have created localizations for English and German, your app will use the language selected in Settings (this is the preferred option).

If you want to set the language directly from your application:

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

will set the language for your application only to English (for German, I assume the key is "de"). You should also:

[[NSUserDefaults standardUserDefaults] synchronize];

This will not take effect until your application restarts.

Answer 6

Have a class "LanguageUtils" with that method :

- (NSString *) localizedString:(NSString *)key
{
    if (self.currentLanguage == nil) {
        self.currentLanguage = @"en";
    }

    NSString* path = [[NSBundle mainBundle] pathForResource:[self.currentLanguage lowercaseString] ofType:@"lproj"];
    NSBundle* languageBundle = [NSBundle bundleWithPath:path];
    return [languageBundle localizedStringForKey:key value:@"" table:nil];
}

And the property NSString currentLanguage.

Then in your .pch do :

#undef NSLocalizedString
#define NSLocalizedString(key, _comment) [[Language sharedInstance] localizedString:key]

Works like a charm and you can redefine the current language at runtime.

Just keep in mind that your view should be refreshed by yourself. It won't automatically do it for you.