Professional Android 2 Development - 8

ANDROID: AN OPEN PLATFORM FOR MOBILE DEVELOPMENT
ANDROID:一个开放的手机开发平台

Google’s Andy Rubin describes Android as:
谷歌的Andy Rubin这样描述Android：
The first truly  open and comprehensive  platform for mobile devices, all of the
software to run a mobile phone but without the proprietary obstacles  that have
hindered mobile innovation. (http://googleblog.blogspot.com/2007/11/
wheres-my-gphone.html)
第一个真正属于手机设备的开放的、综合的平台，所有软件不受专利权的干扰地运行在一台手机上，已经有上百种新手机软件。(http://googleblog.blogspot.com/2007/11/wheres-my-gphone.html)

Put simply, Android is a combination  of three components:
简单地说，Android是由三个组件组合起来的：

➤ A free, open-source operating system for mobile devices
一个运行在手机设备上的免费，开源的操作系统

➤ An open-source development platform for creating mobile applications
一个用来开发手机应用的开源开发平台

➤ Devices, particularly mobile phones, that run the Android operating system and the applications created for it More specifically, Android is made up of several necessary and dependent parts, including the following:
运行Android操作系统和为它创建的应用的设备（尤其是手机）更特别，Android由一组必要的和依赖部分组成，包括以下部分：
➤ A hardware reference design that describes the capabilities required for a mobile device to support the software stack.
➤一组硬件的参考实现，描述了手机设备支撑软件体系所需要的计算能力。

➤ A Linux operating system kernel that provides low-level interface with the hardware, memory management, and process control, all optimized for mobile devices.
➤一个为硬件提供了底层接口的Linux操作系统内核提供，包括存储管理、进程控制等，针对手机设备作了尽可能的优化。

➤ Open-source libraries for application development, including SQLite, WebKit, OpenGL, and a media manager.
➤提供给应用开发的开源库，包括SQLite，WebKit，OpenGL和一个多媒体管理器。

➤ A run time used to execute and host Android applications, including the Dalvik virtual machine and the core libraries that provide Android-specific functionality. The run time is designed to be small and efficient for use on mobile devices.
➤ 一个用于执行和宿主Android应用程序的运行时环境，包括Dalvik 虚拟机和提供Android自身特定功能的核心库。运行时环境为手机设备设计，小巧且有效。

➤ An application framework that agnostically  exposes  system services to the application layer, including the window manager and location manager, content providers, telephony, and sensors.
➤ 一个应用框架向应用层显示所有系统服务，包括窗口管理和位置管理，内容提供，电话和传感器。

➤ A user interface framework used to host and launch applications.
➤ 一个用来宿主和启动应用的用户界面框架。

➤ Preinstalled applications shipped  as part of the stack.
➤ 将预安装应用纳入软件体系。

➤ A software development kit used to create applications, including tools, plug-ins, and documentation.
➤ 用来创建应用程序的一个软件开发工具，包括工具、插件和文档。

What really makes Android compelling  is its open philosophy , which ensures that you can fix  any deficiencies  in user interface or native application design by writing an extension or replacement. Android provides you, as a developer, with the opportunity to create mobile phone interfaces and applications designed to look, feel, and function exactly as you imagine them.
真正让Android引人注目的是它的开放哲学，确保你修复任何在用户界面有缺陷或通过编写代码来扩展或替换本地应用。Android提供给作为程序员的你，通过创建手机界面和程序来设计你想象中的视觉、体验和实际的功能的机会。

NATIVE ANDROID APPLICATIONS
本地ANDROID应用程序

Android phones will normally come with a suite  of generic preinstalled applications that are part of the Android Open Source Project (AOSP), including, but not necessarily limited to:
Android电话通常带有一套通用预装好的应用程序作为Android开源项目的一部分，包括（但不局限在）：

➤ An e-mail client
➤ e-mail客户端

➤ An SMS management application
➤ SMS消息程序

➤ A full PIM (personal information management) suite including a calendar and contacts list
➤ 完整的包括时钟和联系人列表的PIM(个人信息管理)套件

➤ A WebKit-based web browser
➤ 基于WebKit的网页浏览器

➤ A music player and picture gallery
➤ 音乐播放器和画廊

➤ A camera and video recording application
➤ 照相机和视频记录程序

➤ A calculator
➤ 计算器

➤ The home screen
➤ 主屏幕

➤ An alarm clock
➤ 闹钟

In many cases Android devices will also ship with the following proprietary Google mobile applications:
很多时候Android设备经常配有以下谷歌公司所有的手机应用程序：

➤ The Android Market client for downloading third-party Android applications
➤ 用于下载第三方Android应用的Android Market 客户端。

➤ A fully-featured mobile Google Maps application including StreetView, driving directions and turn-by-turn navigation, satellite  view, and traffic conditions
➤ 完整特性的手机谷歌地图程序包括 StreetView，驾驶指南和转向导航，卫星视图和交通情况。

➤ The Gmail mail client
➤ Gmail邮件客户端

➤ The Google Talk instant -messaging client
➤ 谷歌即时语音消息客户端

➤ The YouTube video player
➤ YouTube视频播放器

The data stored and used by many of these native applications — like contact details — are also available to third-party applications. Similarly, your applications can handle  events such as incoming calls or new SMS messages.
这些本地应用存储和使用的数据，比如联系人明细也一样可以被第三方应用使用。简单点说，你的应用可以操作例如来电或有新SMS消息这样的事件。

The exact  makeup  of the applications available on new Android phones is likely to vary  based on the hardware manufacturer and/or the phone carrier or distributor .
新Android手机上对应用程序准确的补充是变化是基于硬件制造商及（或）手机载体或经销商。

The open-source nature of Android means that carriers and OEMs can customize the user interface and the applications bundled  with each Android device. Several OEMs have done this, including HTC with the Sense UI, Motorola with MotoBlur, and Sony Ericsson’s custom UI.
开源的本性对Android意味着束缚在Android设备上的载体和OEM可以用定制用户界面和应用程序。几个OEM已经这样做了，包括HTC的Sense UI，摩托罗拉的MotoBlue，索爱的cutom UI。

It’s important to note that for compatible  devices, the underlying platform and SDK remain consistent  across  OEM and carrier variations. The look and feel of the user interface may vary, but your applications will function in the same way across all compatible Android devices.
设备的可兼容性是需要重点关注的，底层平台和SDK在OEM和载体的多样性面前保持了一致性。对用户界面的视觉和感官可变，但你的应用程序在功能上同样面临着兼容所有Android设备。