在 Xamarin Forms 中更改语言

Question

Long story short: The app I wrote supports multiple language using LangResource.{xx-XX}.resx files in the Translation folder.

I apply the strings directly in xaml using

`xmlns:resources="clr-namespace:Elettric80.TP.Translations"`

in the ContentPage initial declaration, and

`Text="{x:Static resources:LangResource.{string}}"` 

where needed.

On code side i just assign the translated strings using LangResource.{string} .

In page Option, which is a child of MainPage, I offer the possibility to select a language based on the available resx files. Once selected I save the selected lang in the settings and reload the MainPage with

Application.Current.MainPage = new MainPage();

When the app restarts, I read the settings, get the selected language and execute

Thread.CurrentThread.CurrentUICulture = new CultureInfo(lang);
Thread.CurrentThread.CurrentCulture = new CultureInfo(lang);

before InitializeComponent(); is called.

The problem is that the MainPage is translated, but all the other pages keeps the previous language, unless I close the app, and restart it manually.

I also tried to use DependencyService to apply directly the language on Android side calling:

DependencyService.Get<ILanguageService>().SetLanguage(lang);

in c# and passing the language to the following method

public void SetLanguage(string lang)
{
    CultureInfo myCulture = new CultureInfo(lang);
    CultureInfo.DefaultThreadCurrentCulture = myCulture;

    Locale locale = new Locale(lang);
    Locale.Default = locale;
    var config = new global::Android.Content.Res.Configuration();
    config.Locale = locale;
    config.SetLocale(locale);
}

Still, the language changes only if I close the app and open it again. Any suggestion?

Answer 1

I solved this problem with DependencyService , calling

DependencyService.Get<ILanguageService>().SetLanguage(lang);

passing the language that has been selected (in the format "en"/"es"/"it"/etc...).

The interface is declared in ILanguageService.cs as:

namespace {namespace}
{
    public interface ILanguageService
    {
        void SetLanguage(string lang);
    }
}

The Android side is as follows:

[assembly: Dependency(typeof({namespace}.Droid.LanguageService))]

namespace {namespace}.Droid
{
    public class LanguageService : ILanguageService
    {
        public void SetLanguage(string lang)
        {
            if (!string.IsNullOrEmpty(lang))
            {
                // Get application context
                Context context = Android.App.Application.Context;

                // Set application locale by selected language
                Locale.Default = new Locale(lang);
                context.Resources.Configuration.Locale = Locale.Default;
                context.ApplicationContext.CreateConfigurationContext(context.Resources.Configuration);
                context.Resources.DisplayMetrics.SetTo(context.Resources.DisplayMetrics);

                // Relaunch MainActivity
                Intent intent = new Intent(context, new MainActivity().Class);
                intent.AddFlags(ActivityFlags.NewTask);
                context.StartActivity(intent);
            }
        }
    }
}

As before I set the app in the selected language reading it from the settings and applying it with

Thread.CurrentThread.CurrentUICulture = new CultureInfo(lang);
Thread.CurrentThread.CurrentCulture = new CultureInfo(lang);