Android Review notes-Architecture and version

#Android架构:

1. Linux Kernel layer

The Android system is based on the Linux 2.6 kernel, which provides a base for the various hardware of Android devices

Drivers, such as display drivers, audio drivers, camera drivers, bluetooth drivers, Wi-Fi drivers, power management, and more.

2. System Runtime Layer

This layer provides key feature support for Android systems through a number of C + + libraries. such as SQLite Cuiti

Supported by the database, the Opengl|es library provides support for 3D drawings, and the Webkit library provides a browser core

Support and so on.

Also on this tier is the Android runtime library, which mainly provides core libraries that allow developers to

Use the Java language to write Android apps. In addition, the Dalvik virtual machine is included in the Android Runtime library.

It allows each Android app to run in a separate process, with a Dalvik virtual

Machine instance. Compared to Java virtual machines, Dalvik is specifically tailored for mobile devices,

CPU performance is limited and so on the situation has been optimized processing.

3. Application Framework Layer

This layer provides the core of the various api,android that may be used when building the application

Applications are done using these APIs, and developers can build their own applications by using these APIs.

4. Application Layer

All applications installed on the phone belong to this layer, such as the system comes with the contact person, SMS, etc.

program, or a mini-game you download from Google Play, and of course your own program.

#Android版本对应API

Code Name
Version
API level

Lollipop
5.1
API level 22

Lollipop
5.0
API level 21

KitKat
4.4-4.4.4
API level 19

Jelly Bean
4.3.x
API level 18

Jelly Bean
4.2.x
API level 17

Jelly Bean
4.1.x
API Level 16

Ice Cream Sandwich
4.0.3-4.0.4
API level, NDK 8

Ice Cream Sandwich
4.0.1-4.0.2
API level, NDK 7

Honeycomb
3.2.x
API level 13

Honeycomb
3.1
API Level 6, NDK

Honeycomb
3.0
API level 11

Gingerbread
2.3.3-2.3.7
API Level 10

Gingerbread
2.3-2.3.2
API Level 9, NDK 5

Froyo
2.2.x
API Level 8, NDK 4

Eclair
2.1
API Level 7, NDK 3

Eclair
2.0.1
API Level 6

Eclair
2.0
API Level 5

Donut
1.6
API level 4, NDK 2

Cupcake
1.5
API Level 3, NDK 1

(No code name)
1.1
API Level 2

(No code name)
1.0
API Level 1

Android Review notes-Architecture and version