java - How change setting in android app using radiobutton?

Question

im developing weather app and its almost done but there is problem.

i create an Activity called "setting". in that activity i create a group radiobutton To give the user the option to change the temperature unit from C(centigrade) to F(fahrenheit).but i have no idea to how to do it?

i want when user choose F every temperature units change to F.

This my Radio group button:

question from:https://stackoverflow.com/questions/65933672/how-change-setting-in-android-app-using-radiobutton

Answer 1

Save the users choice using SharedPreferences and use it to display the data accordingly.

Settings Activity

private var prefs =
        this.getSharedPreferences("com.example.android.appname", Context.MODE_PRIVATE)

  radioGroup.setOnCheckedChangeListener(RadioGroup.OnCheckedChangeListener { group, checkedId ->
        val userChoice = when(checkedId){
              R.id.radio1 -> "centigrade"
              R.id.radio2 -> "fahrenheit"
        }

      prefs.edit().putString("temparatureMode", userChoice).apply()
  })

// assuming you want to display the data in text field

private var prefs =
        this.getSharedPreferences("com.example.android.appname", Context.MODE_PRIVATE)

val selectedChoice = prefs.getString("temparatureMode", "centigrade")  // assuming centigrade is default mode

val textfield1 = findViewById<TextView>(R.id.textfield1)

textfield1.text = when(selectedChoice){
"centigrade" -> // logic based on centigrade choice
"fahrenheit" -> // logic based on fahrenheit choice
}

check the docs for more info