Gphone--android Learning Notes (i): Android Overview and Tools __android

Google recently officially released its Linux2.6 kernel-based mobile operating system--android, the latest SDK is now available for download, and its app development environment is Java.

Characteristics
Program Framework reusable and reusable components
Dalvik virtual machines optimized for mobile devices
Integrated Browser, which is based on open source WebKit engine development
The optimized graphics system is provided, which consists of a custom 2D graphics library; A 3D graphics library that follows the OpenGL ES 1.0 standard (Hardware acceleration)
Using SQLite to implement structured data storage
Media support for some generic audio, video, and picture formats (MPEG4, H.264, MP3, AAC, AMR, JPG, PNG, GIF)
GSM Technology (Hardware dependent)
Bluetooth, EDGE, 3G and WiFi (dependent hardware)
Camera, GPS, compass, and accelerometer (dependent hardware)
A very rich development environment, including a device simulator, adaptation tools, memory and efficiency tuning tools, and an Eclipse plug-in

Android's structure
The following figure shows the main component structure of the Android operating system. Each section is described in detail in the following paragraphs
Http://code.google.com/android/images/system-architecture.png

Library
Android consists of a C + + library that is used in various components of the Android system. These features are presented to developers through the Android application framework. Some of the core libraries are listed below:

System C Library-implements the Bsd-derived standard C system Library (LIBC) for embedded Linux based devices
Media Libraries-opencore based on PacketVideo; The library provides playback and recording functions for many popular audio and video formats, including static picture files,

Including MPEG4, H.264, MP3, AAC, AMR, JPG, and PNG
Surface Manager-for managing access to graphical display subsystems and 2D and 3D graphics layers for different applications
Libwebcore-a stylish web browser engine that provides implementations for Android browsers and embedded Web view
SGL-Hidden 2D graphics engine
3D Libraries-Library based on OpenGL ES 1.0 APIs implementation; The library is used for 3D graphics acceleration or provides a highly optimized 3D software raster
FreeType-Font rendering for bitmap and vector patterns
SQLite-A powerful, lightweight relational database engine for all applications

Tools
The Android SDK contains a variety of toolset for developing mobile applications on the Android platform. It includes not only the Android emulator and the Android development tool plug-in for Eclipse (ADT),

It also includes a variety of tools for debugging, packaging, and installing applications on the emulator.

Android Emulator
Android Simulator: A phone simulator that runs on a computer. You can use this simulator to design, debug, and test your own developed applications in a real Android environment

。

Android Development Tools Plugin for the Eclipse IDE
The Android Application development tool plug-in for the Eclipse integrated development environment: it adds powerful functionality to the Eclipse integrated development environment, making it easier to create and debug an android application

Single and quick. If you use Eclipse to develop Android apps, the ADT plugin will help you a lot:

You can access other Android development tools from within the Eclipse integrated development environment. For example, ADT allows you to access many features of the DDMS tool directly from Eclipse, including screenshots, management port transfer

Send (port-forwarding), set breakpoints, view thread and process information.
It provides a new Project wizard to quickly create all the basic files needed for a new Android application.
It automates and simplifies the process of building Android apps.
It provides an Android code editor to write valid XML for Android manifest and resource files.
For more information about the ADT plug-in, including installation instructions, see Installing the ADT Plugin for Eclipse. Hello Android Describes a useful example program and process

Order of the effect diagram.

Dalvik Debug Monitor Service (DDMS)
Dalvik Debugging Monitoring service: It is integrated in the Dalvik (Android Platform virtual Machine) for managing processes running on emulators or devices and assisting with debugging. You can use it to kill

Dead processes, selecting a specific program to debug, generate trace data, view heap and thread data, screen shots of emulators or devices, and so on.

Android Debug Bridge (ADB)
Android Debug Bridge: It is used to install an application's. apk file to an emulator or device and access the emulator or device from the command line. can also be used to connect a standard debugger to a running

The application code on the Android emulator or device.

Android Asset Packaging Tool (AAPT)
Android Resource Packaging Tools: You can create. apk files using the AAPT tool, which contains binaries and resource files for Android applications.

Android Interface Description Language (aidl)
Android Interface Description Language: It is used to generate Interprocess interface code. For example, it might be used in a service.

Sqlite3
SQLite3 Database: Android applications can create and use SQLite data files, and developers and users can easily access these sqlite data files.

TraceView
Trace Display tool: It can generate a graphical analysis view of the trace log data. These trace log data are generated by the Android application.

Mksdcard
Create the SD card tool: It helps create disk mirrors. This disk image can simulate an external memory card (such as an SD card) on the emulator.

Dx
DX Tool: It rewrites the. Class bytecode to the Android bytecode (stored in a. dex file).

Activitycreator
Activitycreator: It's a script that generates an ant build file. The ant build file is used to compile the Android application. If you are running in an eclipse environment with the ADT plugin installed

Hair, you don't need this script anymore.