(This book covers the main features of Android platform versions 1.5 to 2.2, as well as the development cases of security practices, and introduces the basic concepts, practical technologies and use modes of Android mobile platform development. The main contents include: platform foundation, development environment construction, program framework, high-end interface and low-level interface design, file system management, network communication, wireless communication, multimedia programming, personal information management, telephone system, database use, XML use and map use. As many as 120 development examples. This book is mainly for developers with certain mobile platform development experience, as well as programmers who are interested in Android platform development. This document includes the following annexes:)