How to create a MultiChoice AlertDialog in Android (Kotlin)

     DESCRIPTION     

In this tutorial we will create a MultipleChoice AlertDialog using Android Studio. We will show list of colors to show in dialog. We will create a Button to show that AlertDialog, and a TextView to show the selected items...

     VIDEO     

     SOURCE CODE     

Step 1: Create a new project OR Open your project

Step 2: Code

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="20dp"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/showsnackbarbtn"
        android:text="Show Alert Dialog"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    <TextView
        android:id="@+id/txtView"
        android:text="Preferred colors"
        android:textSize="20sp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

</LinearLayout>

MainActivity.kt

package com.blogspot.devofandroid.myapplication

import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.support.v7.app.AlertDialog
import android.widget.TextView
import android.widget.Toast
import kotlinx.android.synthetic.main.activity_main.*
import java.util.*

class MainActivity : AppCompatActivity() {

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

        val mSlctdTxtTv = findViewById<TextView>(R.id.txtView)
        showsnackbarbtn.setOnClickListener {
            val builder = AlertDialog.Builder(this@MainActivity)
            // String array for alert dialog multi choice items
            val colorsArray = arrayOf("Black", "Orange", "Green", "Yellow", "White", "Purple")
            // Boolean array for initial selected items
            val checkedColorsArray = booleanArrayOf(true, // Black checked
                    false, // Orange
                    false, // Green
                    true, // Yellow checked
                    false, // White
                    false  //Purple
            )
            // Convert the color array to list
            val colorsList = Arrays.asList(*colorsArray)
            //setTitle
            builder.setTitle("Select colors")
            //set multichoice
            builder.setMultiChoiceItems(colorsArray, checkedColorsArray) { dialog, which, isChecked ->
                // Update the current focused item's checked status
                checkedColorsArray[which] = isChecked
                // Get the current focused item
                val currentItem = colorsList[which]
                // Notify the current action
                Toast.makeText(applicationContext, currentItem + " " + isChecked, Toast.LENGTH_SHORT).show()
            }
            // Set the positive/yes button click listener
            builder.setPositiveButton("OK") { dialog, which ->
                // Do something when click positive button
                mSlctdTxtTv.text = "Your preferred colors..... \n"
                for (i in checkedColorsArray.indices) {
                    val checked = checkedColorsArray[i]
                    if (checked) {
                        mSlctdTxtTv.text = mSlctdTxtTv.text.toString() + colorsList[i] + "\n"
                    }
                }
            }
            // Set the neutral/cancel button click listener
            builder.setNeutralButton("Cancel") { dialog, which ->
                // Do something when click the neutral button
            }
            val dialog = builder.create()
            // Display the alert dialog on interface
            dialog.show()
        }

    }
}

Step 3: Output

MultiChoice AlertDialog in Android (Kotlin)