Android 简明教程
Android - Overview
What is Android?
Android 是一款面向移动设备（如智能手机和平板电脑）的开源和基于 Linux 的 Operating System 。Android 由 Open Handset Alliance（由 Google 和其他公司牵头）开发。
Android is an open source and Linux-based Operating System for mobile devices such as smartphones and tablet computers. Android was developed by the Open Handset Alliance, led by Google, and other companies.
Android 为移动设备的应用程序开发提供了一种统一的方法，这意味着开发人员只需针对 Android 开发即可，而他们的应用程序应该能够在由 Android 提供支持的不同设备上运行。
Android offers a unified approach to application development for mobile devices which means developers need only develop for Android, and their applications should be able to run on different devices powered by Android.
第一个 Android 软件开发工具包（SDK）测试版由 Google 在 2007 年发布，而第一个商业版本 Android 1.0 在 2008 年 9 月发布。
The first beta version of the Android Software Development Kit (SDK) was released by Google in 2007 where as the first commercial version, Android 1.0, was released in September 2008.
2012 年 6 月 27 日，在 Google I/O 大会上，Google 宣布了下一个 Android 版本 4.1 Jelly Bean 。Jelly Bean 是一个增量更新，其主要目的是改善用户界面，在功能和性能方面都是如此。
On June 27, 2012, at the Google I/O conference, Google announced the next Android version, 4.1 Jelly Bean. Jelly Bean is an incremental update, with the primary aim of improving the user interface, both in terms of functionality and performance.
Android 的源代码可在免费和开放源代码软件许可下获得。Google 根据 Apache License 2.0 版本发布了大部分代码，根据 GNU 通用公共许可版本 2 发布了其余代码（Linux 内核更改）。
The source code for Android is available under free and open source software licenses. Google publishes most of the code under the Apache License version 2.0 and the rest, Linux kernel changes, under the GNU General Public License version 2.
Features of Android
Android 是一款与 Apple 4GS 竞争且支持强大功能的操作系统。其中一些列举如下 −
Android is a powerful operating system competing with Apple 4GS and supports great features. Few of them are listed below −
Sr.No. |
Feature & Description |
1 |
Beautiful UI Android OS basic screen provides a beautiful and intuitive user interface. |
2 |
Connectivity GSM/EDGE, IDEN, CDMA, EV-DO, UMTS, Bluetooth, Wi-Fi, LTE, NFC and WiMAX. |
3 |
Storage SQLite, a lightweight relational database, is used for data storage purposes. |
4 |
Media support H.263, H.264, MPEG-4 SP, AMR, AMR-WB, AAC, HE-AAC, AAC 5.1, MP3, MIDI, Ogg Vorbis, WAV, JPEG, PNG, GIF, and BMP. |
5 |
Messaging SMS and MMS |
6 |
Web browser Based on the open-source WebKit layout engine, coupled with Chrome’s V8 JavaScript engine supporting HTML5 and CSS3. |
7 |
Multi-touch Android has native support for multi-touch which was initially made available in handsets such as the HTC Hero. |
8 |
Multi-tasking User can jump from one task to another and same time various application can run simultaneously. |
9 |
Resizable widgets Widgets are resizable, so users can expand them to show more content or shrink them to save space. |
10 |
Multi-Language Supports single direction and bi-directional text. |
11 |
GCM Google Cloud Messaging (GCM) is a service that lets developers send short message data to their users on Android devices, without needing a proprietary sync solution. |
12 |
Wi-Fi Direct A technology that lets apps discover and pair directly, over a high-bandwidth peer-to-peer connection. |
13 |
Android Beam A popular NFC-based technology that lets users instantly share, just by touching two NFC-enabled phones together. |
Android Applications
Android 应用程序通常使用 Android 软件开发工具包以 Java 语言进行开发。
Android applications are usually developed in the Java language using the Android Software Development Kit.
Android 应用程序开发后，可以通过 Google Play 、 SlideME 、 Opera Mobile Store 、 Mobango 、 F-droid 等商店进行轻松打包和出售，也可以通过 Amazon Appstore 进行出售。
Once developed, Android applications can be packaged easily and sold out either through a store such as Google Play, SlideME, Opera Mobile Store, Mobango, F-droid and the Amazon Appstore.
Android 为全球 190 多个国家/地区的数亿部移动设备提供支持。它是所有移动平台中已安装基地最大、增长最快的平台。全世界每天有超过 100 万台新 Android 设备被激活。
Android powers hundreds of millions of mobile devices in more than 190 countries around the world. It’s the largest installed base of any mobile platform and growing fast. Every day more than 1 million new Android devices are activated worldwide.
本教程的编写宗旨在于教授您如何开发和打包 Android 应用程序。我们将从 Android 应用程序编程的环境设置开始，然后深入到 Android 应用程序的各个方面。
This tutorial has been written with an aim to teach you how to develop and package Android application. We will start from environment setup for Android application programming and then drill down to look into various aspects of Android applications.
Categories of Android applications
市场上有许多 android 应用程序。最热门的类别是：
There are many android applications in the market. The top categories are −
History of Android
android 的代号范围目前从 A 到 N，例如：Aestro、Blender、Cupcake、Donut、Eclair、Froyo、Gingerbread、Honeycomb、Ice Cream Sandwitch、Jelly Bean、KitKat、Lollipop 和 Marshmallow。让我们按顺序了解 android 历史。
The code names of android ranges from A to N currently, such as Aestro, Blender, Cupcake, Donut, Eclair, Froyo, Gingerbread, Honeycomb, Ice Cream Sandwitch, Jelly Bean, KitKat, Lollipop and Marshmallow. Let’s understand the android history in a sequence.
What is API level?
Platform Version |
API Level |
VERSION_CODE |
|
Android 6.0 |
23 |
MARSHMALLOW |
|
Android 5.1 |
22 |
LOLLIPOP_MR1 |
|
Android 5.0 |
21 |
LOLLIPOP |
|
Android 4.4W |
20 |
KITKAT_WATCH |
KitKat for Wearables Only |
Android 4.4 |
19 |
KITKAT |
|
Android 4.3 |
18 |
JELLY_BEAN_MR2 |
|
Android 4.2, 4.2.2 |
17 |
JELLY_BEAN_MR1 |
|
Android 4.1, 4.1.1 |
16 |
JELLY_BEAN |
|
Android 4.0.3, 4.0.4 |
15 |
ICE_CREAM_SANDWICH_MR1 |
|
Android 4.0, 4.0.1, 4.0.2 |
14 |
ICE_CREAM_SANDWICH |
|
Android 3.2 |
13 |
HONEYCOMB_MR2 |
|
Android 3.1.x |
12 |
HONEYCOMB_MR1 |
|
Android 3.0.x |
11 |
HONEYCOMB |
|
Android 2.3.4 Android 2.3.3 |
10 |
GINGERBREAD_MR1 |
|
Android 2.3.2 Android 2.3.1 Android 2.3 |
9 |
GINGERBREAD |
|
Android 2.2.x |
8 |
FROYO |
Android 2.1.x |
7 |
ECLAIR_MR1 |
Android 2.0.1 |
|
6 |
ECLAIR_0_1 |
Android 2.0 |
|
5 |
ECLAIR |
Android 1.6 |
|
4 |
DONUT |
Android 1.5 |
|
3 |
CUPCAKE |
Android 1.1 |
|
2 |
BASE_1_1 |
Android 1.0 |