kotlin, Spinner

val spinner = Spinner(this)

var list_of_items = arrayOf("item1", "item2", "item3")

val array_adapter = ArrayAdapter(this, android.R.layout.simple_spinner_item, list_of_items)
array_adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item)

spinner.adapter = array_adapter

spinner.onItemSelectedListener = object : AdapterView.OnItemSelectedListener {

    override fun onItemSelected(parent: AdapterView<*>, view: View, pos: Int, id: Long) {
        //todo : do something
    }
    override fun onNothingSelected(parent: AdapterView<out Adapter>?) {}
}