原文地址：http://developer.android.com/tools/support-library/features.html

在Android?Support Library包中，包含了幾個可以被引入到你應用的庫。每一個庫支持一個特定的Android平臺版本范圍和功能集合。

原文：The Android Support Library package contains several libraries that can be included in your application. Each of these libraries supports a specific range of Android platform versions and set of features.

這個指南解釋了Support Library提供的重要功能和版本，這將幫助你決定你的應用選擇哪一個功能和版本。總的來說，我們推薦引入v4 support和?v7 appcompat的庫，因為它們支持的Android版本很廣泛，并為推薦的用戶界面樣式提供API。

原文：This guide explains the important features and version support provided by the Support Libraries to help you decide which of them you should include in your application. In general, we recommend including the?v4 support?and??v7 appcompat?libraries, because they support a wide range of Android versions and provide APIs for recommended user interface patterns.

想要使用任何下面的庫，你必須將庫文件下載到你安裝的Android SDK中。在Support Library Setup中根據指引下載Support Library，來完成這一步驟。你必須采取額外的措施來引入一個特殊的Support Library到你的應用中。查看下面每一個庫章節(jié)的末尾來獲取重要信息，這些信息闡述了如何將庫引入你的應用中。

原文：In order to use any of the following libraries, you must download the library files to your Android SDK installation. Follow the directions for downloading the Support Libraries in?Support Library Setup?to complete this step. You must take additional steps to include a specific Support Library in your application. See the end of each library section below for important information on how to include the library in your application.


v4 Support Library
這個庫是為Android 1.6（API level 4）和更高版本設計的。相對于其他庫，他包含的API集合最大，包括對應用組件、用戶界面功能、輔助功能、數據處理、網絡連接和編程工具的支持。這里有一些包含在v4庫中的關鍵類：（此處偷個懶，省去關鍵類的翻譯500字^_^）

原文：This library is designed to be used with Android 1.6 (API level 4) and higher. It includes the largest set of APIs compared to the other libraries, including support for application components, user interface features, accessibility, data handling, network connectivity, and programming utilities. Here are a few of the key classes included in the v4 library:


App ComponentsFragment?- Adds support encapsulation of user interface and functionality with Fragments, enabling applications provide layouts that adjust between small and large-screen devices.NotificationCompat?- Adds support for rich notification features.LocalBroadcastManager?- Allows applications to easily register for and receive intents within a single application without broadcasting them globally.User InterfaceViewPager?- Adds a?ViewGroup?that manages the layout for the child views, which the user can swipe between.PagerTitleStrip?- Adds a non-interactive title strip, that can be added as a child of?ViewPager.PagerTabStrip?- Adds a navigation widget for switching between paged views, that can also be used with?ViewPager.DrawerLayout?- Adds support for creating a?Navigation Drawer?that can be pulled in from the edge of a window.SlidingPaneLayout?- Adds widget for creating linked summary and detail views that appropriately adapt to various screen sizes.AccessibilityExploreByTouchHelper?- Adds a helper class for implementing accessibility support for custom views.AccessibilityEventCompat?- Adds support for?AccessibilityEvent. For more information about implementing accessibility, see?Accessibility.AccessibilityNodeInfoCompat?- Adds support for?AccessibilityNodeInfo.AccessibilityNodeProviderCompat?- Adds support for?AccessibilityNodeProvider.AccessibilityDelegateCompat?- Adds support for?View.AccessibilityDelegate.ContentLoader?- Adds support for asynchronous loading of data. The library also provides concrete implementations of this class, including?CursorLoader?and?AsyncTaskLoader.FileProvider?- Adds support for sharing of private files between applications.還有很多其他API包含在這個庫中。在API引用中查看?android.support.v4包，以獲取關于v4 Support Library API的全部和詳細的信息。

原文：There are many other APIs included in this library. For complete, detailed information about the v4 Support Library APIs, see the??android.support.v4?package in the API reference.