Android provides a rich application framework that allows you to build innovative apps and games for mobile devices in a Java language environment. The documents listed in the left navigation provide details about how to build apps using Android's various APIs.

To learn how apps work, start withApp Fundamentals.

To begin coding right away, readBuilding Your First App

Android提供了丰富的应用程序框架，它允许您在Java语言环境中构建移动设备的创新应用程序和游戏。在左侧导航中列出的文档提供了有关如何使用Android的各种API来构建应用程序的详细信息。

要了解如何开发应用，从应用基础开始。

如何开始一个正确的编码，请参照建立你的第一个应用程序。

Apps provide multiple entry points

应用程序提供多个入口点

Apps adapt to different devices

应用程序适应不同的设备

Android apps are built as a combination of distinct components that can be invoked individually. For instance, an individualactivityprovides a single screen for a user interface, and aservice independently performs work in the background.

Android应用程序被构建为能够单独地被调用不同的部件的组合。例如，一个单独的Activity提供了一个单个屏幕上的用户界面，和一个Service独立地在后台中执行工作。

Android provides an adaptive app framework that allows you to provide unique resources for different device configurations. For example, you can create different XML layout files for different screen sizes and the system determines which layout to apply based on the current device's screen size.

Android提供了一个自适应的应用程​​序框架，它允许您为不同的设备配置提供不同的资源。例如，您可以为不同的屏幕尺寸创建不同的XML布局文件并且系统决定了基于当前屏幕尺寸使用哪些布局。

From one component you can start another component using anintent. You can even start a component in a different app, such an activity in a maps app to show an address. This model provides multiple entry points for a single app and allows any app to behave as a user's "default" for an action that other apps may invoke.

从一个组件就可以使用一个Intent启动另一个组件。你甚至可以启动不同应用程序中的一个组件，比如启动一个地图应用中的Activity来显示地址。该模型为一个单一的应用程序提供了多个入口点，并允许任何应用程序的行为作为用户的"默认"，用于其他应用程序调用的Action

You can query the availability of device features at runtime if any app features require specific hardware such as a camera. If necessary, you can also declare features your app requires so app markets such as Google Play Store do not allow installation on devices that do not support that feature.

你可以在运行时查询设备功能的可用性，如果任何应用程序的功能需要特定的硬件如照相机。如果需要，你也可以定义你的应用程序需要的特性，，如Google Play商店不允许不支持该特性的设备安装。

Learn more:

• App Fundamentals
• Intents and Intent Filters
• Activities

  了解更多：

• 应用基础
• 意图和意图过滤器
• Activities

Learn more:

• Device Compatibility
• Resources Overview
• User Interface Overview

  了解更多：

• 设备兼容性
• 资源概述
• 用户界面概述