Book Image

Android Studio 4.0 Development Essentials - Kotlin Edition

By : Neil Smyth
Book Image

Android Studio 4.0 Development Essentials - Kotlin Edition

By: Neil Smyth

Overview of this book

Kotlin as an Android-compatible programming language is becoming increasingly popular. Fully updated for Android Studio 4.0, this book will teach you the skills necessary to develop Android-based applications using Kotlin. Starting with the basics, this book outlines the steps necessary to set up Android development and testing environments, and goes on to introduce you to programming in Kotlin. You’ll practice Java to Kotlin code conversion and explore data types, operators, expressions, loops, functions, as well as the basics of OOP in Kotlin. You’ll then learn about Android architecture components and advanced topics, such as intents, touchscreen handling, gesture recognition, multi-window support integration, and biometric authentication. As you make progress, you’ll explore Android Studio 4.0’s key features, including layout editor, direct reply notifications, and dynamic delivery. You’ll also delve into Android Jetpack and create a sample app project using ViewModel, the Android Jetpack component. Finally, you will upload your app to Google Play Console and model the build process using Gradle. By the end of this Android book, you’ll be fully prepared to develop applications using Android Studio 4.0 and Kotlin.
Table of Contents (97 chapters)
97
Index

53.10 Adding Items to the ListView

Each time the floating action button is tapped by the user, a new item will be added to the ListView in the form of the prevailing time and date. To achieve this, some changes need to be made to the MainActivity.kt file.

Begin by implementing the onStart() method to obtain a reference to the ListView instance and to initialize an adapter instance to allow us to add items to the list in the form of an array:

import android.os.Bundle

import com.google.android.material.snackbar.Snackbar

import androidx.appcompat.app.AppCompatActivity

import android.view.Menu

import android.view.MenuItem

import android.view.View

import android.widget.ArrayAdapter

 

import kotlinx.android.synthetic.main.activity_main.*

import kotlinx.android.synthetic.main.fragment_first.*

import java.util.ArrayList

 

class MainActivity : AppCompatActivity() {

 

    var listItems = ArrayList<String&gt...