在 swift 中即时更改语言

Question

现在知道苹果不推荐这个了

In general, you should not change the iOS system language (via use of the AppleLanguages pref key) from within your application. This goes against the basic iOS user model for switching languages in the Settings app, and also uses a preference key that is not documented, meaning that at some point in the future, the key name could change, which would break your application.

但是，这是一个可以动态更改语言的应用程序，请相信我。我也知道有人在这里问了这个问题：Changing language on the fly, in running iOS, programmatically。然而，这已经过时了，我想知道是否有更新、更好或更简单的方法来做到这一点。目前在我的应用程序中，我有一个语言选择屏幕。单击此视图中的按钮将使用与按钮关联的语言调用以下函数：

 func changeLang(language: String) {

    if language != (currentLang as! String?)! {
        func handleCancel(alertView: UIAlertAction!)
        {

        }
        var alert = UIAlertController(title: NSLocalizedString("language", comment: "Language"), message: NSLocalizedString("languageWarning", comment: "Warn User of Language Change Different Than Defaults"), preferredStyle: UIAlertControllerStyle.Alert)

        alert.addAction(UIAlertAction(title: "Cancel", style: UIAlertActionStyle.Cancel, handler:handleCancel))
        alert.addAction(UIAlertAction(title: "Yes", style: UIAlertActionStyle.Default, handler:{ (UIAlertAction) in

            NSUserDefaults.standardUserDefaults().setObject([language], forKey: "AppleLanguages")
            NSUserDefaults.standardUserDefaults().synchronize()
            println(self.currentLang)

            let alert = UIAlertView()
            alert.title = NSLocalizedString("language", comment: "Sign In Failed")
            alert.message = NSLocalizedString("languageChangeNotification", comment: "Notify of language change")
            alert.addButtonWithTitle(NSLocalizedString("ok", comment: "Okay"))
            alert.show()

            self.performSegueWithIdentifier("welcome", sender: AnyObject?())


        }))
        self.presentViewController(alert, animated: true, completion: {
        })
    } else {
        self.performSegueWithIdentifier("welcome", sender: AnyObject?())
    }

}

示例：

@IBAction func english(sender: UIButton) {
        changeLang("en")

    }

如果用户选择的语言不同于他们自己的语言，他们会收到确认提示，然后被要求重启设备。这就是我想要改变的。看起来 NSUSerDefaults 的这一部分直到应用程序重新启动后才同步。证据：

let currentLang: AnyObject? = NSLocale.preferredLanguages()[0]
println(currentLang)
// Prints english
changeLang("zh-Hans")
println(currentLang)
// Prints english still until restart

苹果目前的国际化系统很好，打算用一下。但是，我如何即时更改语言，也许是通过强制更新 NSUSerDefaults？

编辑： 我建议现在使用此 library 来执行此操作。祝你好运！

Answer 1

基本上你得教你bundle如何通过加载不同的bundle文件来切换语言。

我将我的 Objective-C code 翻译成 Swift — NSBundle 类别保持不变。

结果是一个视图控制器 class，它提供了一个 languageDidChange() 方法来覆盖。

NSBundle+Language.h

#import <Foundation/Foundation.h>

@interface NSBundle (Language)
+(void)setLanguage:(NSString*)language;

@end

NSBundle+Language.m

#import "NSBundle+Language.h"
#import <objc/runtime.h>

static const char associatedLanguageBundle=0;

@interface PrivateBundle : NSBundle
@end

@implementation PrivateBundle
-(NSString*)localizedStringForKey:(NSString *)key
                            value:(NSString *)value
                            table:(NSString *)tableName
{
    NSBundle* bundle=objc_getAssociatedObject(self, &associatedLanguageBundle);
    return bundle ? [bundle localizedStringForKey:key
                                            value:value
                                            table:tableName] : [super localizedStringForKey:key
                                                                                      value:value
                                                                                      table:tableName];
}
@end

@implementation NSBundle (Language)
+(void)setLanguage:(NSString*)language
{
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        object_setClass([NSBundle mainBundle],[PrivateBundle class]);
    });

    objc_setAssociatedObject([NSBundle mainBundle], &associatedLanguageBundle, language ?
                             [NSBundle bundleWithPath:[[NSBundle mainBundle] pathForResource:language ofType:@"lproj"]] : nil, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}
@end

AppDelegate.swift

import UIKit

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?


    func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {

        NSNotificationCenter.defaultCenter().addObserver(self, selector: "languageWillChange:", name: "LANGUAGE_WILL_CHANGE", object: nil)

        let targetLang = NSUserDefaults.standardUserDefaults().objectForKey("selectedLanguage") as? String

        NSBundle.setLanguage((targetLang != nil) ? targetLang : "en")
        return true
    }

    func languageWillChange(notification:NSNotification){
        let targetLang = notification.object as! String
        NSUserDefaults.standardUserDefaults().setObject(targetLang, forKey: "selectedLanguage")
        NSBundle.setLanguage(targetLang)
        NSNotificationCenter.defaultCenter().postNotificationName("LANGUAGE_DID_CHANGE", object: targetLang)
    }    
}

BaseViewController.swift

import UIKit



class BaseViewController: UIViewController {

    @IBOutlet weak var englishButton: UIButton!
    @IBOutlet weak var spanishButton: UIButton!

    deinit{
        NSNotificationCenter.defaultCenter().removeObserver(self)
    }
    override func viewDidLoad() {
        super.viewDidLoad()
        NSNotificationCenter.defaultCenter().addObserver(self, selector: "languageDidChangeNotification:", name: "LANGUAGE_DID_CHANGE", object: nil)
        languageDidChange()

    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    @IBAction func switchLanguage(sender: UIButton) {

        var localeString:String?
        switch sender {
        case englishButton: localeString = "en"
        case spanishButton: localeString = "es"
        default: localeString = nil
        }


        if localeString != nil {
            NSNotificationCenter.defaultCenter().postNotificationName("LANGUAGE_WILL_CHANGE", object: localeString)
        }
    }


    func languageDidChangeNotification(notification:NSNotification){
        languageDidChange()
    }

    func languageDidChange(){

    }


}

ViewController.swift

import UIKit

class ViewController: BaseViewController {

    @IBOutlet weak var helloLabel: UILabel!
    override func viewDidLoad() {
        super.viewDidLoad()
    }

    override func languageDidChange() {
        super.languageDidChange()
        self.helloLabel.text = NSLocalizedString("Hello", comment: "")

    }
}

除了使用 BaseViewController 的子classes，您的视图控制器还可以 post "LANGUAGE_WILL_CHANGE" 并监听 "LANGUAGE_DID_CHANGE"

我把完整的项目推送到这里：ImmediateLanguageSwitchSwift

Answer 2

上面“vikingosegundo”的回答在 Objective c 中有类别所以这是 Swift extension 版本

import ObjectiveC

private var associatedLanguageBundle:Character = "0"

class PrivateBundle: Bundle {
    override func localizedString(forKey key: String, value: String?, table tableName: String?) -> String {
        let bundle: Bundle? = objc_getAssociatedObject(self, &associatedLanguageBundle) as? Bundle
        return (bundle != nil) ? (bundle!.localizedString(forKey: key, value: value, table: tableName)) : (super.localizedString(forKey: key, value: value, table: tableName))

    }
}

extension Bundle {
    class func setLanguage(_ language: String) {
        var onceToken: Int = 0

        if (onceToken == 0) {
            /* TODO: move below code to a static variable initializer (dispatch_once is deprecated) */
            object_setClass(Bundle.main, PrivateBundle.self)
        }
        onceToken = 1
        objc_setAssociatedObject(Bundle.main, &associatedLanguageBundle, (language != nil) ? Bundle(path: Bundle.main.path(forResource: language, ofType: "lproj") ?? "") : nil, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
    }
}

剩余代码将与 "vikingosegundo"

提到的相同

欢迎指正:)

Answer 3

使用这行代码，它会在不关闭应用程序的情况下改变布局。从右到左

UIView.appearance().semanticContentAttribute = .forceRightToLeft

以及从左到右翻转

UIView.appearance().semanticContentAttribute = .forceLeftToRight

如果您想更改文本字段布局或文本更改，请使用此代码，因为我遇到过这个问题。 textfield 的文本不是 changning 布局。检查此代码以更改文本字段文本的布局。

extension UITextField {
  open override func awakeFromNib() {
super.awakeFromNib()
  if UserDefaults.languageCode == "ar" {
    if textAlignment == .natural {
        self.textAlignment = .right
    }
  }
 }
}

在 swift 中即时更改语言

Changing language on the fly in swift

iphone

internationalization

nsuserdefaults

ios

swift