Delve into building Android apps using Kotlin. Gain hands-on experience with tools like Groovy and XML while creating a Travel Blog app for your portfolio.

This course is for anyone looking to build their own Android applications. Ever since Google announced that Kotlin is the language of choice for Android development, Kotlin has become increasingly popular.

In this course, you’ll take a hands-on, project-based approach to developing Android applications. You’ll work with the most common tools that Android developers use every day, including Kotlin, Groovy, and XML. As you learn, you’ll build a fully functional Travel Blog Application that will be a great addition to your portfolio.

By the end of this course, you’ll have tangible experience building an Android application and be ready to build even more complex projects.

John

Great practical approach to learn Android Development

Engineer

Modern Android App Development with Kotlin

# Activity concept

Activity is one of the core components of Android. It represents one screen of the application user interface. 

Usually, an Android application consists of several activities, e.g. the “Travel Blog” application may contain the following activities:

- *LoginActivity* - represents login flow
- *ListActivity* - represents a list of recent article titles
- *DetailActivity* - represents an article itself

Activities can be launched on top of each other, forming an activity back stack. Users can navigate through this back stack via UI (User Interface) components or navigate back via the system back button.

The activity has its own lifecycle, which helps the developer to understand when an activity is created or destroyed, becomes visible or hidden, recreated, or rotated.

# Main activity

To create an activity, we need to create a Kotlin class and extend it from the `Activity` superclass. Here is an example of `MainActivity` in the `com.travelblog` package:

Android Ecosystem

Hello World

Travel Blog - Login Screen

Travel Blog - Details Screen

Travel Blog - List Screen

Travel Blog - Search & Sort

Travel Blog - Offline

Conclusion

Activity

Activity concept