Android SDK, API, and engineering catalog description

description of the package under SDK
1:add-ons:android third-party files and repositories needed for development
2:docs:android's documentation. Includes development guides, API references, resources, and more
3:extras: Extended add-on package
4:platforms: You install all of the downloaded Android platforms and store them in sub-versions
5:platform-tools: Platform-related tools
6:samples: All the sample programs
7:system-images: Pictures used by the system
8:temp: A temporary operation or cached directory

9:tools: Some of the development tools needed to apply the Android platform for Development

Common API Package Description
1:android.app: Provides a high-level program model, provides a basic operating environment
2:android.content: contains a variety of classes for accessing and publishing data on a device
3:android.database: Browse and manipulate the database through the content provider
4:android.graphics: the underlying graphics library, which contains the canvas, color filters, dots, rectangles, which can be drawn directly to the screen by their
.
5:android.location: Classes for targeting and related services
6:android.media: Provides classes to manage multiple audio, video media interfaces
7:android.net: Classes that provide help for network access, More than usual java.net.* interface
8:android.os: Provides system services, message transmission, IPC mechanism
9:android.opengl: tools to provide OpenGL
10:android.provider : Provides class access to Android content provider
11:android.telephony: Provides API interaction with phone calls
12:android.view: Provides the underlying UI interface Framework
13:android.util: Methods involving tools, such as the operation of a time date
14:android.webkit: Default browser Action interface
15:android.widget: contains various UI Element (mostly visible) in the application's screen using the

The directory structure of the

project is described below:
1:assets: Storing native files, files stored in this directory can be packaged in a program. Unlike Res, the
Point is that Android does not generate an ID for a file under assets, and if you use a file under assets, you need to refer to the path and file name of the
file.
2:bin:java The path to the compiled output
3:gen: An R file that is automatically generated by the Android compilation resource file.
4:res: A resource file that is required for a program, that is, a non-Java file. Common directories are:
(1) res/animator/: XML files, defining animation Properties
(2) res/anim/: XML files, which are compiled into frame-by-frames animations (frame by frame
Animation) or motion tweens ( tweened animation) Object
(3) Res/color/:xml file, defining a list of color states
(4) res/layout/: Storing XML files that are compiled into a screen layout (or part of a screen)
(5) res/ Menu/:xml file that defines the menu for the app

(6) res/drawable/: Store image files such as. png,. 9.png,. jpg,. gif, etc. Put it in here.
The image resource may be aapt (Android assert Packaging Tool,android Resource Package
Tool) automatically optimizes for lossless compression. If you do not want the picture to be compressed, please put the image file
In the res/raw/directory, this avoids being automatically optimized.
(7) res/raw/: Copy directly to any file in the device, they do not need to compile
(8) res/values/: Storage can be compiled into many types of resource files, in XML format. Common
The files are:
Array.xml: Defining arrays
Colors.xml: Defines a string value for color drawable and colors.
Dimens.xml defines the dimension value (dimension value).
The Strings.xml defines a string (string) value.
Styles.xml defines a style object.
(9) res/xml/: Any XML file that can be read at run time by calling Resources.getxml ().

5:SRC: Storing Java source code

Project manifest file Androidmanifest.xml: This list gives the Android system information about this
Application, the system must know some information before it can run any program code.
Androidmanifest.xml mainly includes the following features:
(1) A Java package that names the application that uniquely identifies the application
(2) Describe the components of the application: activities, services, broadcast receivers, and content that comprise the application.
A class that implements each component and publishes its capabilities (for example, which intent messages can be processed)
Name. These statements make the Android system aware of these components and under what conditions they can be launched;
(3) Decide which process the application component is running in
(4) Declare the permissions that the application must have to access protected portions of the API, and other
interacting with programs;
(5) Declaring the application's other necessary permissions for the interaction between components;
(6) enumeration of test equipment instrumentation classes to provide the environment configuration required for the application to run
and other information, these statements are only present during the development and testing phases and will be removed before release
(7) Declare the minimum Android API required by the application

Android SDK, API, and engineering catalog description