Kotlin Alertdialog Code

Below is sample code for displaying an Alertdialog using Kotlin. It has 3 button click listeners.

class MainActivity : AppCompatActivity() {

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

        setTitle("Kotlin Alert Dialog")
        showDialog("Kotlin Sample Code", "Alertdialog")

    }

    private fun showDialog(title: String, message: String){
        // Late initialize an alert dialog object
        lateinit var dialog: AlertDialog
        // Initialize a new instance of alert dialog builder object
        val builder = AlertDialog.Builder(this)
        // Set a title for alert dialog
        builder.setTitle(title)
        // Set a message for alert dialog
        builder.setMessage(message)
        // On click listener for dialog buttons
        val dialogClickListener = DialogInterface.OnClickListener{ _, which ->
            when(which){
                DialogInterface.BUTTON_POSITIVE -> {
                    Toast.makeText(this@MainActivity, "POSITIVE button clicked", Toast.LENGTH_LONG).show()
                }
                DialogInterface.BUTTON_NEGATIVE -> {
                    Toast.makeText(this@MainActivity, "NEGATIVE button clicked", Toast.LENGTH_LONG).show()
                }
                DialogInterface.BUTTON_NEUTRAL -> {
                    dialog.dismiss()
                }
            }
        }
        // Set the alert dialog positive/yes button
        builder.setPositiveButton("POSITIVE",dialogClickListener)
        // Set the alert dialog negative/no button
        builder.setNegativeButton("NEGATIVE",dialogClickListener)
        // Set the alert dialog neutral/cancel button
        builder.setNeutralButton("CANCEL",dialogClickListener)
        // Initialize the AlertDialog using builder object
        dialog = builder.create()
        // Finally, display the alert dialog
        dialog.show()
    }
}

Android Kotlin Alertdialog Screenshot