Android Preliminary: Introduction to communication technology && Android

Communication technology:

1G analog formats can only be used for voice calls.

2G GSM, CDMA send and receive SMS and mail.

2.5G GPRS, EDGE access WAP network data. (Pictures, wallpapers, text messages)

3G WCDMA (Unicom), CDMA2000 (Telecom), TD-SCDMA (MOBILE)
Tweet, see high-definition pictures, small movies.

3.5G HSDPA, hsdpa+

4G td-lte Download speed: 50mb/s = 6mb/s upload speed: 10mb/s = 1.2mb/s

100mb/s! = 100mb/s

1 Byte = 8bit

100mb/s = 12.5mb/s

Android history

1.5 Cupcake (Cupcake)
1.6 Donut (Donut)
2.1 Eclair (Lightning puffs)
2.2 Froyo (Frozen Yogurt)
2.3 Gingerbread (ginger cake)
3.0 Honeycomb (Honeycomb) tablet-specific
4.0 Ice cream SandWich (ice cream sandwich)
4.1 Jelly bean (Jelly Bean)
4.2 Jelly Bean (Jelly Bean)
4.3 Jelly bean (Jelly Bean)
4.4 KitKat (Nestle Chocolate)
5.0 Lime Pie (lime pie) not released

The difference between an Android virtual machine and a Java Virtual machine:

JVM:. Java--Javac----and jar---jar
Schema: Stack

DVM:. Java--Javac----Dx.bat
Schema: Register (a high-speed cache on the CPU)

Troubleshoot problems with Android SDK manager not downloading SDK

Unable to update and download SDK due to mainland's interception of Google server

Append the following information in the Hosts file (directory: C:\WINDOWS\SYSTEM32\DRIVERS\ETC):
74.125.113.121 developer.android.com
203.208.46.146 dl.google.com
203.208.46.146 dl-ssl.google.com

Noun Explanation: ADB Android Debug Bridge Android

Android Debug Bridge: adb command uses
You need to append the full path of the Adb.exe to the path in the system environment traversal
D:\IDE\adt-bundle-windows-x86-20130729\sdk\platform-tools

Common command Operations (you need to configure Adb.exe environment variables):

1, ADB devices----------------list all the equipment

2. ADB start-server----------------open adb service

3. ADB kill-server----------------close adb service

4, adb logcat----------------View Log

5, adb shell----------------mount to the Linux space (similar to operating under the Linux system)

6. ADB Install < application (add extension) >----------------installation Application

7. Adb–s < simulator name > install < application (plus extension) >----------------installation applied to the specified emulator
8, adb uninstall < package name >----------------Uninstall application, to be uninstalled according to the package name of the program

9. ADB pull <remote> <local>----------------copy files from remote server (Android) to native

10. ADB push <local> <remote>----------------Copy Local files to the remote host (Android)

11. Emulator–avd < simulator name >----------------manually launch Android virtual machine

12, CTRL + F11 screen switch----------------in the virtual machine shortcut keys for the screen switch

Directory description of Android in Eclipse

Project directory Structure:
SRC: Storing Java code
Gen: Storing automatically generated files. R.java Store the ID of the corresponding resource under the Res folder
Project.Properties: Specifies the version of the development kit used by the current project
Libs: The jar package that the current project relies on.
Assets: The media files required to place some programs.
Bin: The compilation Directory of the project. Store some temporary files generated at compile time and the. apk file for the current project.
Res (Resources): Resource file.
Drawable: The picture used to store the program.
Layout: Store the android layouts file.
Menu: Stores the layout of the Android optionsmenu menu.
Values (the data required by the application. IDs are generated in the R file)
Strings.xml holds Android strings.
Dimens.xml the size used to store the screen fit.
Style.xml stores the styles displayed under Android.
VALUES-SW600DP values for 7-inch plates
Values-sw720dp-land values for 10-inch plates
VALUES-V11 Specifies the style that is displayed for phones above the 3.0 version.
VALUES-V14 Specifies the style that is displayed for phones above the 4.0 version.
The portal file for the AndroidManifest.xml:android application. The components inside Android are declared. and related configuration information.
Proguard-project.txt: Encrypts the current program used.

Android Package app and install the process

Compiling the Classes.dex file (see slide 20)
Compiling the RESOURCES.ARSC file
1. The resource file is converted from Text Format compilation to binary format.
2, source Index table RESOURCES.ARSC.
3, RESOURCES.ARSC converted into binary format.

ADB (Android Debug Bridge) provides developers with the convenience
IDE Eclipse automatically implements all of the above processes.

Package installation process (Run as Android application):
1. Build the APK file.
1). Generate the. dex file.
2). Generate RESOURCES.ARSC for the Resource Index table.
3). Prepare the files that are not compiled.
4). The. manifest file Androidmenifest.xml file is converted to binary.
5). Use Debug.keystore to package and sign the entire application.

2. Load the APK file into the emulator.
Load the apk file into/data/local/tmp/xxx.apk

3. Install the application.
1). Put the/data/local/tmp/xxx.apk file, cut the/data/app/package name -1.apk
2). Under the/data/data/folder, create a folder with the package name to store the data for the current program.
3). Add a separate record in the Packages.xml and packages.list files.

Android Preliminary: Introduction to communication technology && Android