Did you get dizzy by Android Private Libraries, referenced Libraries, Android dependency?

The function and usage of V4, V7 and V13

1. What is Android support V4, V7, V13?
is essentially three Java libraries.

2. Why should I have a support library?

?? is to solve the software compatibility problem. If you are developing an application on a low-version Android platform, and the application wants to use a feature that is later, you need to use the support library.
?? Android API has always been high version compatible with low version. API-8 (android2.2) will be compatible with Api-4 (Android 1.6). But instead, you build an APK using the 2.2 platform version, and if you want to be able to run on 1.6, You need to do backwards compatibility.
?? Android Support-xx is Google's official backwards-compatible package. As the name suggests, it helps the build program to be backwards compatible to version 1.6. But it's not everything, but it's limited.
?? Android in order to be compatible with 2. X the following version, so out of the ANDROID.SUPPORT.V4 package, the main purpose of the package is to facilitate the developer in the 2.X development environment, the use of 4.0 of the control.

3. What are the differences and roles of three support libraries?

?? A brief explanation of the differences between these versions:

• Android Support V4: This package is designed to take care of 1.6 and later, this package is the most widely used, Eclipse new project, when the default comes with.

• Android Support V7: This package is designed to take care of 2.1 and above, but does not include lower, so if you do not consider 1.6, we can add this package, in addition to note that V7 is to rely on V4 This package, that is, two must be included at the same time.

• Android Support V13: This package is designed for Android 3.2 and later, generally we are not used, tablet development can be used.

What exactly is in the 4.Android support package?

Http://www.2cto.com/kf/201411/350928.html

See a Java EE project (developed using MyEclipse)

• The jar inside the JRE system LIBRARY:JRE System Library is a class library (a lot of jar packages) that the Java runtime relies on.

• The jar inside Java EE 5 Libraries:java EE libraries is the class library (a lot of jar packages) that runs Web engineering dependencies.

• Referenced libraries: is the class library that the project needs to refer to, here is the reference of the object under Lib directly.

• LIB: The jar package required to put the various projects of a third party. Adding the jar package into LIB, the system automatically loads the jar into the referenced libraries.

See an Android project (using Eclipse development)

• Android4.4: Directly supported jar package, we develop software can not V4, with the contents of this package can also, but for compatibility, must use V4.

• Android Private Libraries: Represents a jar package reference placed inside a libs, considered a private reference. It is the Android private library (in the Libs directory). Add jar package to libs inside, the system automatically loads the jar into the Android private libraries; Private Libraries is the map of the jar package inside the Libs! You remove the jar package from the Libs in the Private libraries.

• Libs: No longer explained

?? In fact there is also an Android Dependency, temporarily do not know the difference between Android Dependency and Android Private libraries:
?? One of Baidu's answers:
?? Android Private libraries refers to a third-party jar package, dependencies is a referenced libraries.

?? What is the difference between a library and a jar package in Java?
?? A library is a collection of. jar files. In general, a number of. class files can implement a set of functions, which can then be packaged into a. jar file. For example, when you need to use the collection class, we need an import java.uitl.*; The corresponding is a jar package (. jar file) inside it is a bunch of. class files.
?? Basically there is no difference, but you can understand that: Lib is generally more than the regularization of things, and jar package inside is any person can play, but the specific use of how big that is not necessarily. But if it is better, then Lib is basically the same as the jar package.

Summarize

?? Comparing the structure of two projects, it can be seen that Google has not followed the standard Eclipse project structure and has its own standards.

Another point of knowledge:

?? What does the order and export under build path in Eclipse do?
?? When building the order and exporting which resources to export, order is to use the Order of class (because it is possible to have a class with the same name), export is to use some of the Lib and project published simultaneously.
?? In the order and export entry, the jar package cannot be repeatedly penetrated into the APK, now Android will export the jar is divided into Android dependencies and Android Private libraries two kinds, for developers to choose , but in general these two are going to go into the APK!

Thanksgiving

Android Internship notes (3) fragment with app package or V4 package parsing
Http://www.it165.net/pro/html/201411/26897.html

Tourism Project _android Development compilation Environment Setting summary
http://blog.csdn.net/wangyihero8/article/details/43730207

The difference between the use of the fragment in the app Pack and the fragment in the V4 package
http://blog.csdn.net/a465456465/article/details/10415211

_____________________________ Sorry, please forgive me, thank you, I love you

Did you get dizzy by Android Private Libraries, referenced Libraries, Android dependency?