When I click on AlertDialog item, the radio group not stay ON when close and open alert dialog again-CodePudding

I want to the Radiogroup stay ON when I click on an item from the alertdialog (My AlertDialog) and when I close and open alertdialog again, it still staying ON (Like This)

I also used [checkeditem: 0] to hold radiogroup always ON just for arrayof("English"). but I dont want be always on English Item, I want to it change by selecting each arrayof[("English","فارسی")]

here is my codes: 1- the MainActivity.kt:

import android.content.DialogInterface
import android.content.res.Configuration
import android.os.Bundle
import android.widget.Button
import androidx.appcompat.app.AlertDialog
import androidx.appcompat.app.AppCompatActivity
import java.util.*

class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    loadLocale()
    setContentView(R.layout.activity_main)
    val actionBar = supportActionBar!!
    actionBar.title = resources.getString(R.string.app_name)
    val changeLang = findViewById<Button>(R.id.changeMyLang)
    changeLang.setOnClickListener { showChangeLanguageDialog() }
}

private fun showChangeLanguageDialog() {
    val mBuilder = AlertDialog.Builder(this@MainActivity)
    val listItems = arrayOf("English", "فارسی")
    mBuilder.setSingleChoiceItems(listItems, checkeditem: 0) { dialogInterface: DialogInterface, i: Int ->
        if (i == 0) {
            setLocale("en")
            recreate()
        } else if (i == 1) {
            setLocale("fa")
            recreate()
        }
        dialogInterface.dismiss()
    }
    val mDialog = mBuilder.create()
    mDialog.show()
}

private fun setLocale(lang: String?) {
    val locale = Locale(lang)
    Locale.setDefault(locale)
    val config = Configuration()
    config.locale = locale
    baseContext.resources.updateConfiguration(config, baseContext.resources.displayMetrics)
    val editor = getSharedPreferences("Settings", MODE_PRIVATE).edit()
    editor.putString("My_Lang", lang)
    editor.apply()
}

private fun loadLocale() {
    val prefs = getSharedPreferences("Settings", MODE_PRIVATE)
    val language = prefs.getString("My_Lang", "")
    setLocale(language)
}
}

2- the activity_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
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:orientation="vertical"
android:gravity="center"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/welcome"
    android:textSize="30sp" />

<EditText
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:hint="@string/email" />

<EditText
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:hint="@string/password" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/login" />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/signup" />

<Button
    android:id="@ id/changeMyLang"
    android:layout_marginTop="20dp"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/login" />

</LinearLayout>

I used dialogInterface.dismiss() and dialogInterface.cancel() but none of them hold the radiogroup ON. thank you for helping me. take care.

CodePudding user response：

Replace your method with below one,

private fun showChangeLanguageDialog() {
            val pref = getSharedPreferences("Settings", MODE_PRIVATE)
    
            val mBuilder = AlertDialog.Builder(this@MainActivity)
            val listItems = arrayOf("English", "فارسی")
    
            var checkedItem = 0
            if (pref.getString("My_Lang", "en").equals("en")) {
                checkedItem = 0
            } else if (pref.getString("My_Lang", "en").equals("fa")) {
                checkedItem = 1
            }
    
            mBuilder.setSingleChoiceItems(listItems, checkedItem) { dialogInterface: DialogInterface, i: Int ->
                if (i == 0) {
                    setLocale("en")
                    recreate()
                } else if (i == 1) {
                    setLocale("fa")
                    recreate()
                }
                dialogInterface.dismiss()
            }
            val mDialog = mBuilder.create()
            mDialog.show()
    }