Book Image

Android Studio 3.5 Development Essentials - Java Edition

By : Neil Smyth
Book Image

Android Studio 3.5 Development Essentials - Java Edition

By: Neil Smyth

Overview of this book

Android applications have become an important part of our daily lives and lots of effort goes into developing an Android application. This book will help you to build you own Android applications using Java. Android Studio 3.5 Development Essentials – Java Edition first teaches you to install Android development and test environment on different operating systems. Next, you will create an Android app and a virtual device in Android Studio, and install an Android application on emulator. You will test apps on physical Android devices, then study Android Studio code editor and constraint layout, Android architecture, the anatomy of an Android app, and Android activity state changes. The book then covers advanced topics such as views and widgets implementation, multi-window support integration, and biometric authentication, and finally, you will learn to upload your app to Google Play console and handle the build process with Gradle. By the end of this book, you will have gained enough knowledge to develop powerful Android applications using Java.
Table of Contents (86 chapters)
86
Index

40.9 Modifying the onOptionsItemSelected() Method

When items are selected from the menu, the overridden onOptionsItemsSelected() method of the application’s activity will be called. The role of this method will be to identify which item was selected and change the background color of the layout view to the corresponding color. Locate and double-click on the app -> java -> com.ebookfrenzy.menuexample -> MainActivity file and modify the method as follows:

package com.ebookfrenzy.menuexample;

 

import com.google.android.material.floatingactionbutton.FloatingActionButton;

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

import androidx.appcompat.app.AppCompatActivity;

import androidx.appcompat.widget.Toolbar;

import android.view.View;

import android.view.Menu;

import android.view.MenuItem;

import androidx.constraintlayout.widget.ConstraintLayout;

 

public class MainActivity extends AppCompatActivity {

.

.

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