Kotlin SharedPreferences - Save ListView items and load them

Question

I have a ListView with items created by

 val values = ArrayList().toMutableList()
 val adapter = ArrayAdapter(this, R.layout.listview_text_col         


        

Answer 1

Thank you Arfrmann for posting a working resolution that I could use. I had to modify the code to fit inside a Fragment as well as my values being a MutableList of integers. So, I thought I'd share my scenario so that others could benefit.

class NeedsmetFragment : Fragment() {

    private var incorrectList = mutableListOf()
    val PREFS_FILENAME = "com.app.app.prefs"

    private fun saveData() {
        val sharedPreferences = context!!.getSharedPreferences(PREFS_FILENAME, 0)
        val editor = sharedPreferences.edit()
        val gson = Gson()
        val json = gson.toJson(incorrectList)
        editor.putString("incorrectList", json)
        editor.apply()
    }

    private fun loadData() {
        val sharedPreferences = context!!.getSharedPreferences(PREFS_FILENAME, 0)
        val gson = Gson()
        val json = sharedPreferences.getString("incorrectList", "")
        val type = object: TypeToken>() {}.type

        if(json == null || json == "")
            incorrectList = mutableListOf()

        else
            incorrectList = gson.fromJson(json, type)
    }
    //...
    x++

    incorrestList.add(x)
    saveData()


    loadData()
    thisval = incorrectList[x]


}