How to dynamically update a ListView on Android Kotlin?

This example demonstrates how to dynamically update a ListView on Android Kotlin.

Step 1 − Create a new project in Android Studio, go to File ? New Project and fill all required details to create a new project.

Step 2 − Add the following code to res/layout/activity_main.xml.

<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    android:orientation="vertical"    android:padding="4dp">    <EditText       android:id="@+id/editText"       android:layout_width="match_parent"       android:layout_height="wrap_content"       android:hint="Enter an item here"       android:inputType="text" />    <Button       android:id="@+id/btnAdd"       android:layout_width="wrap_content"       android:layout_height="wrap_content"       android:layout_below="@id/editText"       android:text="Add item" />    <ListView       android:id="@+id/listView"       android:layout_width="fill_parent"       android:layout_height="wrap_content"    android:layout_below="@id/btnAdd" /> </RelativeLayout>

Step 3 − Add the following code to src/MainActivity.kt

import androidx.appcompat.app.AppCompatActivity import android.os.Bundle import android.widget.ArrayAdapter import android.widget.Button import android.widget.EditText import android.widget.ListView class MainActivity : AppCompatActivity() {    lateinit var editText: EditText    lateinit var button: Button    lateinit var listView: ListView    var list: ArrayList<String> = ArrayList()    lateinit var arrayAdapter: ArrayAdapter<String>    override fun onCreate(savedInstanceState: Bundle?) {       super.onCreate(savedInstanceState)       setContentView(R.layout.activity_main)       title = "Kotlin"       listView = findViewById(R.id.listView)       editText = findViewById(R.id.editText)       button = findViewById(R.id.btnAdd)       arrayAdapter = ArrayAdapter(this, android.R.layout.simple_list_item_1, list)       button.setOnClickListener {          list.add(editText.text.toString())          editText.setText("")          arrayAdapter.notifyDataSetChanged()          listView.adapter = arrayAdapter       }    } }

Step 4 − Add the following code to androidManifest.xml

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="app.com.kotlipapp">    <application       android:allowBackup="true"       android:icon="@mipmap/ic_launcher"       android:label="@string/app_name"       android:roundIcon="@mipmap/ic_launcher_round"       android:supportsRtl="true"       android:theme="@style/AppTheme">       <activity android:name=".MainActivity">          <intent-filter>             <action android:name="android.intent.action.MAIN" />             <category android:name="android.intent.category.LAUNCHER" />          </intent-filter>       </activity>    </application> </manifest>

Let's try to run your application. I assume you have connected your actual Android Mobile device with your computer. To run the app from android studio, open one of your project's activity files and click the Run  icon from the toolbar. Select your mobile device as an option and then check your mobile device which will display your default screen −

Click here to download the project code.