How to pass activity values to another activity (Kotlin)

Question

I am a new learner for Kotlin and I am trying to make a setting activity for my app and I want this activity to pass it's values to other activities. I tried different codes but none of them works and I tried to make a shared preference file but I don't know how to write the code

to be clear, I want to pass the font types from setting [main] activity to another activity but i don't know how!

my Main Activity

val preferences = applicationContext.getSharedPreferences("MyPrefs", Context.MODE_PRIVATE)
    val prefEditor = preferences.edit()

    val fonts = arrayOf("Data1", "Data2", "Data3", "Data4")
    val adapterCountry = ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, fonts)
    val spinner = findViewById(R.id.spinner) as Spinner
    spinner.adapter = adapterCountry
    spinner.setSelection(preferences.getInt("position", 0))

    spinner.onItemSelectedListener = object : AdapterView.OnItemSelectedListener {

        override fun onItemSelected(parent: AdapterView<*>, view: View, position: Int, id: Long) {
            spinner.setSelection(position)
            prefEditor.putInt("position", position)
            prefEditor.apply()
            val selecteditem = parent.getItemAtPosition(position).toString()
            if (selecteditem == "Data1"){

            }
        }

        override fun onNothingSelected(parent: AdapterView<*>) {
        }
    }

and this is my main 2 activity:

class Main2Activity : AppCompatActivity() {

internal lateinit var sh : SharedPreferences
override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main2)

    sh = PreferenceManager.getDefaultSharedPreferences(this)





}

override fun onStart() {
    super.onStart()
    if (sh.getBoolean("positon", false)){
        when(sh.getInt("position", 0)){
           0->{
               t1.typeface = Typeface.createFromAsset(assets, "andlso.ttf")
           }
            1->{
                t1.typeface = Typeface.createFromAsset(assets, "frsspbl")
            }
        }
    }


}

i found the solution of this question here it is enter link description here

Try rewrite [this answear](https://stackoverflow.com/questions/5726662/store-application-global-data#5728369) to Kotlin. — Hubert Bossy, Aug 26 '18 at 21:58
If it's just from that activity to the other and theyre linked, consider just passing an intent extra. Otherwise if you do need it app-wide using preferences is a good way: https://developer.android.com/training/data-storage/shared-preferences — P Fuster, Aug 26 '18 at 23:54

score 1 · Answer 1 · answered Aug 27 '18 at 00:00

Intent has already existing functionality to send information from one activity to another.

// in your first activity:

val intent = Intent(context, Main2Activity::class.java)
               .putExtra("position", position)
startActivity(intent)

// in your second activity, you can fetch the extras like this:

class Main2Activity : AppCompatActivity() {

  override fun onCreate(savedInstanceState: Bundle?) {
      super.onCreate(savedInstanceState)
      val position = intent.getIntExtra("position", -1)

  }
}

I don't recommend using shared preferences to pass events between screens because you can get stuck in awkward states if your app crashes before it can cleanup it's shared pref state.

it said that context doesn't have a classifier – Abdulrhman Alanazi Aug 27 '18 at 01:59 — Abdulrhman Alanazi, Aug 27 '18 at 01:59

score 1 · Accepted Answer · answered Aug 27 '18 at 02:21

So basically you want to pass data (font type) in Int from an activity to another one. You can use SharedPrefenrences but it isn't recommended in Android.

I give you 2 solutions:

1. Using bundle

MainActivity.kt

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val fonts = arrayOf("Data1", "Data2", "Data3", "Data4")
        val adapterCountry = ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, fonts)
        val spinner = findViewById(R.id.spinner) as Spinner
        spinner.adapter = adapterCountry

        spinner.onItemSelectedListener = object : AdapterView.OnItemSelectedListener {

            override fun onItemSelected(parent: AdapterView<*>, view: View, position: Int, id: Long) {
                spinner.setSelection(position)
                val selecteditem = parent.getItemAtPosition(position).toString()
                if (selecteditem == "Data1") {

                }

                // Start another activity with position
                val intent = Intent(this@MainActivity, Main2Activity::class.java)
                intent.putExtra("position", position);
                startActivity(intent)
            }

            override fun onNothingSelected(parent: AdapterView<*>) {
            }
        }
    }
}

Main2Activity.kt

class Main2Activity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        val position = intent.getIntExtra("position", 0)
    }
}

2. Using SharedPreferences

MainActivity.kt

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val preferences = PreferenceManager.getDefaultSharedPreferences(this)

        val fonts = arrayOf("Data1", "Data2", "Data3", "Data4")
        val adapterCountry = ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, fonts)
        val spinner = findViewById(R.id.spinner) as Spinner
        spinner.adapter = adapterCountry
        spinner.setSelection(preferences.getInt("position", 0))

        spinner.onItemSelectedListener = object : AdapterView.OnItemSelectedListener {

            override fun onItemSelected(parent: AdapterView<*>, view: View, position: Int, id: Long) {
                spinner.setSelection(position)
                val selecteditem = parent.getItemAtPosition(position).toString()
                if (selecteditem == "Data1"){

                }

                // Save position to prefs.
                preferences.edit()
                        .putInt("position", position)
                        .apply()
            }

            override fun onNothingSelected(parent: AdapterView<*>) {
            }
        }
    }
}

Main2Activity.kt

class Main2Activity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        // Get position from prefs.
        val position = PreferenceManager.getDefaultSharedPreferences(this).getInt("position", 0)
    }
}

Can you tell me how do you get data in other screen?. In you case just using `intent.getIntExtra("position", 0)` or `intent.getIntExtra("position1", 0)`. — Son Truong, Jan 02 '19 at 01:21

How to pass activity values to another activity (Kotlin)

2 Answers2