Book Image

Xamarin 4.x Cross-Platform Application Development - Third Edition

By : Jonathan Peppers
Book Image

Xamarin 4.x Cross-Platform Application Development - Third Edition

By: Jonathan Peppers

Overview of this book

Xamarin is a leading cross-platform application development tool used by top companies such as Coca-Cola, Honeywell, and Alaska Airlines to build apps. Version 4 features significant updates to the platform including the release of Xamarin.Forms 2.0 and improvements have been made to the iOS and Android designers. Xamarin was acquired by Microsoft so it is now a part of the Visual Studio family. This book will show you how to build applications for iOS, Android, and Windows. You will be walked through the process of creating an application that comes complete with a back-end web service and native features such as GPS location, camera, push notifications, and other core features. Additionally, you’ll learn how to use external libraries with Xamarin and Xamarin.Forms to create user interfaces. This book also provides instructions for Visual Studio and Windows. This edition has been updated with new screenshots and detailed steps to provide you with a holistic overview of the new features in Xamarin 4.
Table of Contents (19 chapters)
Xamarin 4.x Cross-Platform Application Development - Third Edition
About the Author
About the Reviewer
Customer Feedback

Understanding Android activities

The Android operating system is very focused on the concept of an activity. An activity is a task or unit of work that users can perform on their screen. For example, users would perform a phone activity for dialing a number and carry out a second activity for interacting with their address book to locate the number. Each Android application is a collection of one or more activities that users can launch and press the hardware's back key on their device to exit or cancel. The user's history is kept in the Android back stack, which you can manipulate from code in special cases. When a new activity starts, the previous one is paused and maintained in memory for later use, unless the operating system is running low on memory.

Activities are loosely coupled with each other; in some ways, you can think of them as having completely separate states from one another in memory. Static classes, properties, and fields will persist the life of the application, but the...