appLocale setting in android studio

Question

I have made radio group where user can select their desire language and app language changes to selected language but i am not able to use the functions (not sure how to!)

Answer 1

NOTE

You can download source code from github repo

Mark current language radio input as selected

Then you need to save your locale change flag/state inside SharedPreferences

SAMPLE CODE follow these steps

Create one class name PrefManager

import android.content.Context;
import android.content.SharedPreferences;

public class PrefManager {
    private SharedPreferences.Editor editor;
    private Context mContext;
    private SharedPreferences prefs;
    private final String LANGUAGE = "language";
    private final String PREF = "user_data";

    public PrefManager(Context mContext) {
        this.mContext = mContext;
    }

    public String getLanguage() {
        this.prefs = this.mContext.getSharedPreferences(PREF, 0);
        return this.prefs.getString(LANGUAGE, "en");
    }

    public void setLanguage(String language) {
        this.editor = this.mContext.getSharedPreferences(PREF, 0).edit();
        this.editor.putString(LANGUAGE, language);
        this.editor.apply();
    }
}

Now add below code/ condition in your settingsActivity.java

public class JavaActivity extends AppCompatActivity {

    PrefManager prefManager;
    RadioButton radio_indo, radio_english;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_java);
        prefManager = new PrefManager(this);
        radio_indo = findViewById(R.id.radio_indo);
        radio_english = findViewById(R.id.radio_english);

        if (prefManager.getLanguage().equals("en")) {
            radio_english.setChecked(true);
        } else {
            radio_english.setChecked(true);
        }
    }

}

Make changes when user select another radio button

• When the user changes the language you need to update it SharedPreferences
• You need to restart or recreate your activity after locale change

Note : you should use RadioGroup.OnCheckedChangeListener() instead of android:onClick="onRadioButtonClicked"

SAMPLE CODE

public class JavaActivity extends AppCompatActivity {

    PrefManager prefManager;
    RadioButton radio_indo, radio_english;
    RadioGroup appLang;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_java);
        prefManager = new PrefManager(this);

        radio_indo = findViewById(R.id.radio_indo);
        radio_english = findViewById(R.id.radio_english);
        appLang = findViewById(R.id.appLang);

        if (prefManager.getLanguage().equals("en")) {
            radio_english.setChecked(true);
        } else {
            radio_english.setChecked(true);
        }

        appLang.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(RadioGroup radioGroup, int checkId) {
                switch (checkId) {
                    case R.id.radio_indo:
                        prefManager.setLanguage("id");
                        // you need to restart or recreate your activity after locale change
                        break;
                    case R.id.radio_english:
                        prefManager.setLanguage("en");
                        // you need to restart or recreate your activity after locale change
                        break;
                }
            }
        });
    }

}

Please follow this my previous answer to change locale runtime

https://stackoverflow.com/a/52270630/7666442