Differences between android4.0 and android2.3

Google has released Android since. After downloading the source code, there is no time to read it. You just need to check the joystick framework code.

The Android system is upgraded almost every six months. Each generation of Android systems is named after a dessert,

Version 1.5 is called cupcake)

Version 1.6 is donut (donut)

2.0/2.1 name: é Clair (lightning puff, a French cream sandwich dessert)

Froyo Version 2.2 (frozen yogurt)

Version 2.3 is gingerbread (ginger pie)

Version 3.0 is called honeycomb and

Version 4.0 is called ice cream sandwich (ice cream sandwich ). Take C
Sequence of d e f g h Headers

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Information found from the Internet: (transferred from http://www.enet.com.cn/article/2011/1130/A20111130943222.shtml)

1. The new UI is more user-friendly

I believe that all my friends who are interested in Android have read the Android system interface released on the Internet earlier. Take a look at the photo at the press conference this time.
 
2. New notification system

The notification system of Android 4.0 has been greatly improved. You can decide which applications can send notifications by yourself.

The android 4.0 notification system can now directly slide to the side to delete notification entries. Such operations also appear in the Application Management list.

3. Voice Input System and facial recognition

Duarte said that the keyboard of the new system has greatly improved error correction and accuracy. He also demonstrated the Voice Input System, saying "Smiley Face" inserts a smiling face directly into the input box.

4. New Android Browser

The android 4.0 browser now supports offline storage of the complete webpage. Better than third-party applications, this feature is now fully integrated with the default browser. Enables real-time preview. With a single gesture, you can close all browser tags and quickly access your desktop website. It can automatically synchronize data with chrome.

5. significantly enhanced Gmail

The Gmail of Android 4.0 is greatly enhanced. When you browse emails, Slide left and right to switch between the previous email and the next email. In addition, the offline search function is added to access emails received in the past 30 days. The new Gmail interface fully integrates the session mode, greatly enhancing Gmail.

6. data usage management

The data tracing system integrated with Android 4.0 can track and analyze mobile data traffic and set the maximum usage of mobile data. It is integrated into the system and has complete functions. The future of third-party data traffic management tools is worrying.

Friends who are always afraid of exceeding the traffic every month don't have to worry about this. The traffic management tool can also view the traffic generated by each application.

7. Enhancement of the photo Mode

The photos taken by Android 4.0 can be shared to any SNS services such as G +, Facebook, and Twitter in just three clicks. If the photos are introduced by the Chinese bank, they will certainly be shared by Renren and Sina Weibo.

The new photo app of Android 4.0 now supports filters like Instagram, photo frames, and panoramic shooting. In addition, the camera can recognize faces and integrate zero shutter technology to quickly respond to the shutter, making the camera fast.

8. Newly Added people Application

The people application is the evolution of the address book, focusing on contact photos. The interface slides rather than clicks.

The people application integrates other communication tools, such as Twitter, LinkedIn, and Google +. In case of exceptions, it also supports adding third-party services by itself.

People application is integrated with Gmail. Click the Avatar in the email to bring up a quick contact method with large photos. You can quickly contact each other through Gmail, information, and third-party services.

9. Android Beam Application

Android beam is an NFC-based sharing method. The two Android phones that support NFC can share the content on the machine with one click back to back. This function is also available to third parties.

10. Other functions

In Android 4.0, you can press the power key and volume key to remove the need for other software.

Added the new "Roboto" font for HD display and real-time wallpaper.

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In fact, this can be done in one sentence: Google's next-generation android
4.0 the system has a completely new UI designed to simplify the interface and improve the running speed. The system has a brand new wallpaper built in. It emits light when you use the touch button on your mobile phone. It also provides voice input, face recognition, photo editing, traffic monitoring, and Android beam functions.

Three design principles: to please users, to simplify life, and to make a difference, android4.0 follows these principles in design, so it is a major upgrade.

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But for digital TV developers, the focus is on the following highlights:

1. Newly Designed UI with first-class new UI, simplified interface, and improved Running Speed

2. The running speed is greatly improved

3. The system has no requirements for hardware.

4. Improved game support

How are they completed? the literal meaning cannot be determined. Let's read the frameworks code and get a general idea.

Hardware code: added hwcomposer. H (hints are set by the Hal and read by surfaceflinger); added audio and camera, which was not available in the past 2.3; divided gralloc into GPU and Fb separately processed modules, it is clearer.

Bionic Standard C code: Although 393 files have been changed, the main function has not changed.
Build involves the compilation rules of the entire android system. The difference is 82 files, and there is no comparison view, which will be involved in later development and compilation process.
Frameworks core framework code: This part must be the biggest change point. From the new UI design feature, we can see that there are 3100 different files and about 9000 files are added, this change is quite big, and it should be the core point of the real upgrade.
Libcore: it is related to the code of the media playback framework. I will further study it later.
Dalvik Virtual Machine: A total of 671 files have been changed. In this case, I am reading the Design Code of 2.3 virtual machines and then writing it separately later.
Libcore: it is related to the code of the media playback framework. I will further study it later.
System: among them, core is about minimizing the startup Environment Code, and extras is the code for the underlying debugging and check tools, with 257 different files
Prebuild: the tool chain is basically the same as the previous version, but the arm-eabi-4.4.3 used by arm was modified, the specific point is unknown
External: added some open source library code
The SDK and ndk have nothing to do with porting.

The entire code is too large, from about 1 GB of the original 2.3 version to about GB of Code. The Code added and modified has been learned for a long time, the best way is to watch and learn while doing it. Naturally, you will be familiar with it.