c# - Is there way to change language while app running

Question

everyone. :) I have App with a multi-layout and I'm trying to change the language while running the app. I find this code to help me change the language

using Android.Content;
using Android.OS;

using Java.Util;

namespace RuntimeAppLanguage
{
    internal class LanguageManager
    {
        private const string MYLANGUAGE = "myLanguage";
        private const string MYPREF = "myPreference";

        public static Context LoadLanguage(Context context)
        {
            var loadedLanguage = GetLanguage(context, Locale.Default.Language);
            return ChangeLanguage(context, loadedLanguage);
        }

        public static Context ChangeLanguage(Context context, string language)
        {
            SaveLanguage(context, language);
            if (Build.VERSION.SdkInt >= BuildVersionCodes.N)
            {
                return ChangeForAPI24(context, language);
            }
            return ChangeForLegacy(context, language);
        }

        private static string GetLanguage(Context context, string Language)
        {
            var privatePreference = context.GetSharedPreferences(MYPREF, FileCreationMode.Private);
            return privatePreference.GetString(MYLANGUAGE, Language);
        }

        private static void SaveLanguage(Context context, string language)
        {
            var privatePreference = context.GetSharedPreferences(MYPREF, FileCreationMode.Private);
            var editor = privatePreference.Edit();
            editor.PutString(MYLANGUAGE, language);
            editor.Apply();
        }

        private static Context ChangeForAPI24(Context context, string language)
        {
            // for api >= 24
            var locale = new Locale(language);
            Locale.Default = locale;
            var configuration = context.Resources.Configuration;
            configuration.SetLocale(locale);
            configuration.SetLayoutDirection(locale);

            return context.CreateConfigurationContext(configuration);
        }

        private static Context ChangeForLegacy(Context context, string language)
        {
            var locale = new Locale(language);
            Locale.Default = locale;
            var resources = context.Resources;
            var configuration = resources.Configuration;
            configuration.Locale = locale;
            resources.UpdateConfiguration(configuration, resources.DisplayMetrics);
            return context;
        }
    }
}

and I'm trying to make it work at this layout but I end up with loop :(

what I'm trying to do is when the user checks English the Arabic switch turn to uncheck and so on.

<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:minWidth="25px"
    android:minHeight="25px">
    <LinearLayout
        android:orientation="horizontal"
        android:minWidth="25px"
        android:minHeight="25px"
        android:layout_width="386.5dp"
        android:layout_height="wrap_content"
        android:id="@+id/linearLayout1"
        android:background="#ffb39ddb">
        <Button
            android:text="Back"
            android:layout_width="80.0dp"
            android:layout_height="match_parent"
            android:id="@+id/back"
            android:background="#ffb39ddb"
            android:drawableLeft="@drawable/arrowangle"
            android:textSize="18dp" />
        <TextView
            android:text="Languagus"
            android:layout_width="222.0dp"
            android:textColor="#FF010101"
            android:textSize="20dp"
            android:layout_height="match_parent"
            android:id="@+id/textView1"
            android:gravity="center"
        />
    </LinearLayout>
    <LinearLayout
        android:orientation="vertical"
        android:minWidth="25px"
        android:minHeight="25px"
        android:layout_width="match_parent"
        android:layout_height="134.5dp"
        android:id="@+id/linearLayout2"
        android:layout_marginTop="0.0dp"
        android:layout_below="@id/linearLayout1"
        android:background="#ffbdbdbd"
        >
        <Switch
            android:layout_width="match_parent"
            android:layout_height="59.0dp"
            android:id="@+id/switch1"
            android:background="#ffffffff"
            android:layout_marginTop="5dp"
            android:text="  English"
            android:textSize="25dp"
            android:textStyle="normal"
            android:checked="false" />
        <Switch
            android:layout_width="match_parent"
            android:layout_height="59.0dp"
            android:id="@+id/switch2"
            android:background="#ffffffff"
            android:layout_marginTop="5dp"
            android:text="  Arabic"
            android:textSize="25dp" />
    </LinearLayout>
</RelativeLayout>

please help me :(

Answer 1

i write a simple sample with "Chinese","English" and "Thailand",whether it meets your needs:

1.the LanguageManager class,the code is the same as above.

2.MainActivity which includes a TextView and a Button;

3.in BaseActivity

public class BaseActivity: AppCompatActivity
{
    protected override void AttachBaseContext(Context @base)
    {
        base.AttachBaseContext(LanguageManager.LoadLanguage(@base));
    }

}

4.in SettingActivity which could set the language,the axml similar to yours

public class SettingActivity : BaseActivity, CompoundButton.IOnCheckedChangeListener
{
    private Switch swCh;
    private Switch swEn;
    private Switch swTh;
    private Bundle s;
    protected override void OnCreate(Bundle savedInstanceState)
    {
        base.OnCreate(savedInstanceState);
        SetContentView(Resource.Layout.setting);
        // Create your application here
        initView();
    }

    private void initView()
    {
        Button back = FindViewById<Button>(Resource.Id.back);
        back.Click += delegate { Finish(); };
        swCh = FindViewById<Switch>(Resource.Id.switch1);
        swEn = FindViewById<Switch>(Resource.Id.switch2);
        swTh = FindViewById<Switch>(Resource.Id.switch3);
        var s = GetSharedPreferences("myPreference", FileCreationMode.Private).GetString( "myLanguage", Locale.Default.Language);
        switch (s)
        {
            case "ch":
                swCh.Checked = true;
                break;
            case "en":
                swEn.Checked = true;
                break;
            case "th":
                swTh.Checked = true;
                break;
        }
        swCh.SetOnCheckedChangeListener(this);
        swEn.SetOnCheckedChangeListener(this);
        swTh.SetOnCheckedChangeListener(this);
    }

    public void OnCheckedChanged(CompoundButton buttonView, bool isChecked)
    {
        if (isChecked)
        {

        switch (buttonView.Id)
        {
            case Resource.Id.switch1:
                swEn.Checked = false;
                swTh.Checked = false;
                LanguageManager.ChangeLanguage(this, "ch");
                break;
            case Resource.Id.switch2:
                swCh.Checked = false;
                swTh.Checked = false;
                LanguageManager.ChangeLanguage(this, "en");
                    break;
            case Resource.Id.switch3:
                swEn.Checked = false;
                swCh.Checked = false;
                LanguageManager.ChangeLanguage(this, "th");
                    break;
        }
             //restart application to change language
            Intent intent = new Intent(this, typeof(MainActivity));
            intent.SetFlags(ActivityFlags.ClearTask | ActivityFlags.NewTask);
            StartActivity(intent);
        }
    }

}

5.create values-en, values-th which include strings for each language

• a.values/strings

  <string name="change_language">改变语言</string>
  <string name="setting">设置</string>
  <string name="chinese">中文</string>
  <string name="english">英语</string>
  <string name="thailand">泰语</string>
  

• b.values-en/strings

  <string name="change_language">change language</string>
  <string name="setting">setting</string>
  <string name="chinese">chinese</string>
  <string name="english">english</string>
  <string name="thailand">thailand</string>
  

• c.values-th/strings

  <string name="change_language">???????????</string>
  <string name="setting">??????</string>
  <string name="chinese">??????</string>
  <string name="english">??????</string>
  <string name="thailand">?????????</string>
  

ps: all the content of Text should use @string/*** and each language use the same name in the values/string

like this effect: