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

31.7 Android Lifecycles

The duration from when an Android component is created to the point that it is destroyed is referred to as the lifecycle. During this lifecycle, the component will change between different lifecycle states, usually under the control of the operating system and in response to user actions. An activity, for example, will begin in the initialized state before transitioning to the created state. Once the activity is running it will switch to the started state from which it will cycle through various states including created, started, resumed and destroyed.

Many Android Framework classes and components allow other objects to access their current state. Lifecycle observers may also be used so that an object receives notification when the lifecycle state of another object changes. This is the technique used behind the scenes by the ViewModel component to identify when an observer has restarted or been destroyed. This functionality is not limited to Android framework...