Search icon
Arrow left icon
All Products
Best Sellers
New Releases
Books
Videos
Audiobooks
Learning Hub
Newsletters
Free Learning
Arrow right icon
Android Programming with Kotlin for Beginners

You're reading from  Android Programming with Kotlin for Beginners

Product type Book
Published in Apr 2019
Publisher Packt
ISBN-13 9781789615401
Pages 698 pages
Edition 1st Edition
Languages
Author (1):
John Horton John Horton
Profile icon John Horton

Table of Contents (33) Chapters

Android Programming with Kotlin for Beginners
Contributors
Preface
1. Getting Started with Android and Kotlin 2. Kotlin, XML, and the UI Designer 3. Exploring Android Studio and the Project Structure 4. Getting Started with Layouts and Material Design 5. Beautiful Layouts with CardView and ScrollView 6. The Android Lifecycle 7. Kotlin Variables, Operators, and Expressions 8. Kotlin Decisions and Loops 9. Kotlin Functions 10. Object-Oriented Programming 11. Inheritance in Kotlin 12. Connecting Our Kotlin to the UI and Nullability 13. Bringing Android Widgets to Life 14. Android Dialog Windows 15. Handling Data and Generating Random Numbers 16. Adapters and Recyclers 17. Data Persistence and Sharing 18. Localization 19. Animations and Interpolations 20. Drawing Graphics 21. Threads and Starting the Live Drawing App 22. Particle Systems and Handling Screen Touches 23. Android Sound Effects and the Spinner Widget 24. Design Patterns, Multiple Layouts, and Fragments 25. Advanced UI with Paging and Swiping 26. Advanced UI with Navigation Drawer and Fragment 27. Android Databases 28. A Quick Chat Before You Go Other Book You May Enjoy Index

Reloading data with SharedPreferences


Let's see how we can reload our data the next time the app is run. This code will reload the three values that the previous code saved. We could even declare our variables and initialize them with the stored values:

val username  = prefs.getString(
   "username", "new user")

val age  = prefs.getInt("age", -1)

val subscribed = prefs.getBoolean(
    "newsletter-subscriber", false)

In the previous code, we load the data from disk using the function appropriate for the data type and the same label we used to save the data in the first place. What is less clear is the second argument to each of the function calls.

The getString, getInt, and getBoolean functions require a default value as the second argument. If there is no data stored with that label, it will then return the default value.

We could then check for these default values in our code and go about trying to obtain the required values or handling an error. For example, see the following code:

if ...
lock icon The rest of the chapter is locked
Register for a free Packt account to unlock a world of extra content!
A free Packt account unlocks extra newsletters, articles, discounted offers, and much more. Start advancing your knowledge today.
Unlock this book and the full library FREE for 7 days
Get unlimited access to 7000+ expert-authored eBooks and videos courses covering every tech area you can think of
Renews at ₹800/month. Cancel anytime}