n##1 Before switching to Android Studio

I have written this guide to cover the basics of what you need to know before migrating your Eclipse projects over the Android Studio. If you have a large and gnarly project to migrate from Eclipse over to Android Studio, consider saving time by booking an hour or two with an AirPair expert who has done it before. Otherwise, read on!

##2 Say Good-bye To Work Spaces And Sub-Projects

Workspace in Eclipse

In Eclipse, you are probably familiar with the concept of a "Workspace." You likely even have an Android project currently which includes multiple component projects and libraries which are compiled into ".jar" files and included in the final resulting application. In Android Studio, projects are replaced with a new concept called "Modules" and "Library Modules."

##3 Hello Modules

Modules are a "discrete unit of functionality that can be run, tested, and debugged independently" and are somewhat similar to an Eclipse project with a few key differences.

Each Module needs to have it's own Gradle build file(generally automatically generated for you when you create a new one, otherwise you can generate them if you are exporting a project from Eclipse). These Gradle files contain important details such as supported Android version ranges, dependencies and other meta-data about your Android project.

Just like in Eclipse, some Modules may be "Library Modules" which are conceptually the same as "Library projects."

##4 Hello Improved Interface Designer

Interface Designer Perspective

Android Studio features a new and improved interface design perspective where you can view the interface you are working on and its related components.Eclipse also has a similar design perspective so it shouldn't be too big of a shock for you. In Eclipse, a "perspective" is used for providing views and visible actions, as well as delivering mechanisms for interaction with resources, multi-tasking and information filtering.

##5 Including Jar Dependencies

Jar Dependencies

Like Eclipse, you will often need to link to JAR files created by 3rd parties. However, you will now need to get used to adding these .jar dependencies to your Gradle build file. Just like Eclipse, you will keep these .jar files in a "libs" folder at the root of your module (e.g. project) directory.

Simply "Right-Click" .jar files in your "libs" directory and select "Add As Library" and your selected JAR files will automatically be added as Gradle dependencies in the relevant build.gradle file for your Module. Make sure to always click "Sync Gradle" to ensure the project has been properly notified of the new dependency on these modules.

##6 Adding Module Dependencies

Just like in Eclipse, one Module may depend on another Module. Follow these instructions to establish a dependency between two modules and Android Studio will automatically generate the necessary Gradle entries you will need.

##7 Manifest Destiny

One major change you will need to get used to with Android Studio is that several common items and settings which once lived in the Android Manifest now are either automatically added (as in the case of the "debuggable=true" flag indicating an Android application may be debugged) or have been moved to build.gradle such as version codes and API min / max specifications. Feature and permission requirements, however, must still be declared in the Manifest as before (e.g. "permission: camera" and so on).

##8 Get Help From An Android Expert

One thing that may be helpful is to enlist the help of a seasoned Android Studio expert to walk you through the nuances of the new IDE. Put in a request on AirPair to get paired with an expert - You will likely be surprised by how much ground you can cover in a short period of time talking to a real person.

##9 Migrating From Android Studio

Read my guide on how to migrate from Android Studio to Eclipse to get specifics on the mechanics of exporting and importing an existing Eclipse project over to Android Studio. There are a number of potential issues that can occur along the way which I won't go into extensive detail on here.

##10 Gradle Basics

The addition of Gradle is going to be your largest hurdle during your transition over to Android Studio. Here are the basics of what you need to know:

Your Android Studio project will have a settings.gradle for the whole project

The settings.gradle file includes references to all modules which are included in the project and is generally updated automatically when you import or create a new module

Each Android Studio module will have its own build.gradle file

If one module depends upon another module, you will need to add that dependency in the build.gradle under the dependencies section

If your Module requries a jar file, it must be listed in that Module's build.gradle file

You may add remote dependencies to your project by listing them in a module's build.gradle file

From time to time, you will need to manually edit these gradle files Read more about Gradle over here.

##11 Unit Testing

Android Studio comes complete with support for JUnit unit and Android tests, read more here. Setting up and running Unit Tests involves creating a few test classes and adding them to your project's run configuration. Follow the linked guide for more specifics. Popular testing frameworks such as Roboguice are not quite supported at this time but it wouldn't surprise me if they are in the near future.

##12 Importing Remote Dependencies With Maven

Android Studio allows you to import remote library files from Maven Central. Browse Maven Central for remote libraries you might be interested in and follow these instructions to ensure these dependencies are automatically downloaded at compile time.

So those are the basics of what you need to know. Android Studio is under rapid development and seems to be getting better every week so go check it out.