(As an Android usage and development book, this book is suitable for both Android beginners and high-end readers who have some Android development experience but need development cases. This book is divided into three parts, 18 chapters in total, and introduces each development detail of Android from simple to deep. This book has a detailed foundation, rich examples and solid cases. From basic to case, it covers three major areas of Android use and development: basic use, network use and game use. What readers need to learn is exactly what this book describes. This document includes the following annexes:)