Android App Development Fundamentals for Beginners

Introduction

Android is one of the famous operating systems which is used for developing android mobile applications. It is based on the Linux kernel. More than 75% mobile devices across the world use android as an operating system for running android applications. That's why Android app development is growing rapidly in popularity amongst aspiring software developers. It's a great way to get into the exciting world of mobile app development, and it's relatively simple to learn the basics. Whether you're just getting started with Android app development or you're looking to brush up on your existing skills, the fundamentals are essential to creating successful apps.

Programming Languages used in Android

Android supports a wide range of programming languages, tools, and libraries that allow developers to create innovative, attractive and highly functional apps.

Java is the most popular language for building Android apps. It is an object-oriented language with a syntax based on C and C++. Java is used for developing the back-end of the application, such as networking, data storage, and user authentication. Java is also used for creating the user interface of the app.

Kotlin is a statically-typed programming language designed to interoperate with Java and to be more concise than Java. It is a modern language that is easy to learn and is gaining popularity as an alternative to Java for Android development.

Kotlin is an official language for Android development which is recommended by Google. So it is beneficial to learn the Kotlin programming language for building android mobile applications.

Android Components

Android is one of the most popular mobile operating systems today. It has become the go-to platform for developers to create mobile applications for a wide range of purposes. Android applications are composed of several basic building blocks that together make the program. These building blocks include activities, services, content providers, broadcast receivers, and resources.

An activity is an interactive user interface that allows users to interact with the application. It is the primary way a user interacts with an Android application. Activities are usually responsible for displaying the application's user interface on the screen and responding to user input.

Services are components that run in the background, without a user interface. They allow applications to perform tasks without requiring a user to be involved. Services are typically used to perform long-running tasks such as downloading a file or sending data to a server.

Content providers are components used to share data between applications. They provide an interface for applications to access and query data stored in a database. This allows applications to share data without the need for a server.

Broadcast receivers are components used to receive and react to system-wide broadcast messages. An application can register a broadcast receiver to receive a broadcast message sent by the system or other applications.

Lifecycle of an activity in Android Application

Android application life cycles are an important concept to understand when developing mobile apps. An activity is a single, focused thing that a user can do. Activities are the building blocks of an Android app and are the entry points for the user. The lifecycle of an activity is the sequence of states that an activity goes through, from when it is first created to when it is destroyed.

When an activity is created, the system calls the onCreate() method. This is where you should initialize the activity, such as creating the user interface, setting up any view objects, and registering any listeners.

After onCreate(), the system calls the onStart() method. This is where the activity becomes visible to the user.

The onResume() method is called when the activity is ready to start interacting with the user.

When an activity is no longer visible to the user, the onPause() method is called. This is where you should save any data that needs to persist across activities.

After onPause(), the system calls the onStop() method. This is where you can release any resources that the activity is using, such as cleaning up any open connections.

When an activity is completely destroyed, the system calls the onDestroy() method. This is where you should release any system resources that the activity was using, such as shutting down any background threads or closing any open databases.

Android Studio Project File Structure

The Android Studio project structure is a hierarchical view of the project files and folders. It provides an overview of the project layout and makes it easy to navigate between the files and folders. The project structure includes the app, build, gradle and manifest files, as well as the main source code folders: src, res, and assets. The app folder contains the application's source code and resources. It includes the main Java source code, resources, and an Android manifest file. The build folder contains the compiled code, resources and other related files that are generated when the application is built. The gradle folder contains the configuration files for the project, such as build scripts, settings and dependencies. The manifest file contains the application's manifest information, such as the application's name, version, and permissions.

Conclusion

In the above article we have taken a look at different fundamentals for Android application development which we must follow to become a successful android developer.