+ In this document
+ +-
+
- Creating an Android Project +
- Create a New Project +
- Select Form Factors and API Level +
- Add an Activity +
- Configure Your App +
- Develop Your App +
- Creating an Android Module + +
- Setting up a Library Module + +
- Referencing a Library Module + +
- Setting up an App Eng Module + +
- Using the Android Project View + +
-
+
Android Studio provides graphical tools for creating and managing Android projects, which +contain everything that define your Android apps, from app source code to build configurations and +test code. Each project contains one or more different types of modules, such as + application modules, library modules, and test modules.
+ +This guide explains how to create Android projects and different modules using +Android Studio. +For more information about the Android project structure and module types, read Managing Projects Overview.
+ + + +Creating an Android Project
+ +Android Studio makes it easy to create Android apps for several form factors, such as phone, +tablet, TV, Wear, and Google Glass. The New Project wizard lets you choose the form factors +for your app and populates the project structure with everything you need to get started.
+ +Follow the steps in this section to create a project in Android Studio.
+ +Step 1: Create a New Project + +
If you didn't have a project opened, Android Studio shows the Welcome screen. +To create a new project, click New Project.
+ +If you had a project opened, Android Studio shows the development environment. +To create a new project, click File > New Project.
+ +The next window lets you configure the name of your app, the package name, and the location +of your project.
+ +
+Figure 1. Choose a name for your project.
+ +Enter the values for your project then click Next.
+ +Step 2: Select Form Factors and API Level + +
The next window lets you select the form factors supported by your app, such as phone, tablet, +TV, Wear, and Google Glass. The selected form factors become the application modules witin the +project. For each form factor, you can also select the API Level for that app. To get more information, +click Help me choose.
+ +
+Figure 2. Select the API Level.
+ +The API Level window shows the distribution of mobile devices running each version of Android, +as shown in figure 3. Click on an API level to see a list of features introduced in the corresponding +version of Android. This helps you choose the minimum API Level that has all the features that +your apps needs, so you can reach as many devices as possible. Then click OK.
+ +
+Figure 3. Choose form factors for your app.
+ +Then, on the Form Factors Window, click Next.
+ + +Step 3: Add an Activity + +
The next screen lets you select an activity type to add to your app, as shown in figure 4. +This screen displays a different set of activities for each of the form factors you selected earlier.
+ +
+Figure 4. Add an activity to your app.
+ +Choose an activity type then click Next.
+ +Note: If you choose "Add No Activity", click Finish + to create the project.
+ + +Step 4: Configure Your Activity + +
The next screen lets you configure the activity to add to your app, as shown in figure 5.
+ +
+Figure 5. Choose a name for your activity.
+ +Enter the activity name, the layout name, and the activity title. Then click +Finish.
+ + +Step 5: Develop Your App + +
Android Studio creates the default structure for your project and opens the development +environment. If your app supports more than one form factor, Android Studio creates a module folder +with complete source files for each of them as shown in figure 6.
+ +
+Figure 6. The default project structure for a mobile app.
+ +Now you are ready to develop your app. For more information, see the following links:
+ + + + +Creating an Android Module
+ +Android application modules contain the src/main/, AndroidManifest.xml,
+ build.gradle, build output and other files you need to generate your app's APK files.
+ Android Studio provides a New Module Wizard that you can use to quickly create a new
+ Android module (or a module from existing code) based on selected application settings, such as
+ minimum SDK level and activity template.
To create a new module, select File > New > + Module. Select the desire module type then click Next to enter the basic module + settings:
+ +-
+
- Enter an Application Name. This name is used as the title of your + application launcher icon when it is installed on a device. + +
- Enter a Module Name. This text is used as the name of the folder where + your Java-based activity files are stored. + +
- Enter a Package Name and Package Location. This class
+ package namespace creates the initial
+ package structure for your applications code files and is added as the
+
package+ attribute in your application's + Android manifest file. + This manifest value serves as the unique identifier for your application app when you + distribute it to users. The package name must follow the same rules as packages in the Java + programming language.
+
+ - Select the Minimum required SDK.
+ This setting indicates the lowest version of the Android platform that your application
+ supports for the selected form factor. This value sets the
+
minSdkVersionattribute in the build.gradle file.
+
+ - Select a Target SDK. This setting indicates the highest version of
+ Android with which you have tested with your application and sets the
+
targetSdkVersionattribute in your application's' build.gradle file. + + + - Select a Compile With API version. This setting specifies what version + of the SDK to compile your project against. We strongly recommend using the most recent + version of the API. + +
- Select a Language Level API version. This setting specifies what version + of the SDK to compile your project against. We strongly recommend using the most recent + version of the API. + +
- Select a Theme. This setting specifies which standard Android + visual style is applied to your + application. Select activity template. For more information about Android code templates, see + Using Code TemplatesLeave the + Create activity option checked so you can start your + application with some essential components. + +
- Click the check box for the required Support Libraries then click Next. + +
- In the Configure Launcher Icon page, create an icon and options, then click + Next. + +
- In the Create Activity page, select activity template then click + Next. For more information about Android code templates, see + Using Code Templates. + + +
- Review the new module settings then click Finish. + +
Note: You can manually change the minimum and target SDK + for your module at any time: Double-click the module's build.gradle in the Project Explorer, + set the targetSdkVersion and targetSdkVersion in the + defaultConfig section.
+ + +The wizard creates a new Android application module according to the options you have chosen.
+ + + +Setting up a Library Module
+ +A library module is a standard Android module, so you can create a new one in the same way + as you would a new application module, using the New Module wizard and selecting Android + Library as the module type. The created library module will appear in your project view + along with the other modules.
+ +You can easily change an existing application module to a library module by changing the + plugin assignment in the build.gradle file to com.android.libary.
+ +
+apply plugin: 'com.android.application'
+
+android {...}
+
+
+
+apply plugin: 'com.android.library'
+
+android {...}
+
+
+
+ Adding a dependency on a library module
+ +The library dependency can be declared in the module's manifest file or in the
+
A library modules's manifest file must declare all of the shared components that it includes, + just as would a standard Android application. For more information, see the documentation for + AndroidManifest.xml.
+ +For example, the TicTacToeLib example library
+ project declares the activity GameActivity:
+<manifest> + ... + <application> + ... + <activity android:name="GameActivity" /> + ... + </application> +</manifest> ++ + +
To add the dependency declaration to the build file, edit the build file for the app
+module (app/build.gradle) and add a dependency on the lib module:
+...
+dependencies {
+ ...
+ compile project(":lib")
+}
+
+
+In this example, the lib module can still be built and tested independently, and
+the build system creates an AAR package for it that you could reuse in other projects.
Note: The library settings in the app/build.gradle
+file will override any shared library resources declared in the manifest file.
Referencing a library module
+ +If you are developing an application and want to include the shared code or resources from a + library module, you can also do so easily by adding a reference to the library module in the + module's dependency page.
+ +To add a reference to a library module, follow these steps:
+ +-
+
- Make sure that both the module library and the application module that depends on it are + in your proejct. If one of the modules is missing, import it into your project. + +
- In the project view, right-click the dependent module and select + Open > Module Settings. + +
- Right-click the plus icon to add a new dependencies.
+
If you are adding references to multiple libraries, you can set their relative + priority (and merge order) by selecting a library and using the Up and + Down controls. The tools merge the referenced libraries with your application + starting from lowest priority (bottom of the list) to highest (top of the list). If more than one + library defines the same resource ID, the tools select the resource from the library with higher + priority. The application itself has highest priority and its resources are always used in + preference to identical resource IDs defined in libraries.
+
+
+ - Use the Scope drop-down to select how the dependency will be applied. + +
- Click Apply to create the dependency and OK to close the + Project Structure window. +
Android Studio rebuilds the module, including the contents of the library module the next time + the project or module is built.
+ + + +Declaring library components in the manifest file
+ +In the manifest file of the application module, you must add declarations of all components
+ that the application will use that are imported from a library module. For example, you must
+ declare any <activity>, <service>,
+ <receiver>, <provider>, and so on, as well as
+ <permission>, <uses-library>, and similar elements.
Declarations should reference the library components by their fully-qualified package names, + where appropriate.
+ +For example, the TicTacToeMain example
+ application declares the library activity GameActivity like this:
+<manifest> + ... + <application> + ... + <activity android:name="com.example.android.tictactoe.library.GameActivity" /> + ... + </application> +</manifest> ++ +
For more information about the manifest file, see the documentation for AndroidManifest.xml.
+ + +Using the Android Project View
+ + +The Android project view in Android Studio shows a flattened version of your project's structure +that provides quick access to the key source files of Android projects and helps you work with +the new Gradle-based build system. The +Android project view:
+ +-
+
- Groups the build files for all modules at the top level of the project hierarchy. +
- Shows the most important source directories at the top level of the module hierarchy. +
- Groups all the manifest files for each module. +
- Shows resource files from all Gradle source sets. +
- Groups resource files for different locales, orientations, and screen types in a single group +per resource type. +
+Figure 9: Show the Android project view.
+Enable and use the Android Project View
+ +The Android project view is not yet enabled by default. To show the Android project view, +click Project and select Android, as shown in figure 9.
+ +The Android project view shows all the build files at the top level of the project hierarchy +under Gradle Scripts. Each project module appears as a folder at the top +level of the project hierarchy and contains these three elements at the top level:
+ +-
+
java/- Source files for the module.
+manifests/- Manifest files for the module.
+res/- Resource files for the module.
+
Figure 10 shows how the Android project view groups all the instances of the
+ic_launcher.png resource for different screen densities under the same element.
Note: The Android project view shows a hierarchy that helps you +work with Android projects by providing a flattened structure that highlights the most commonly +used files while developing Android applications. However, the project structure on disk differs +from this representation.
+ +
+Figure 10: The traditional project view (left) and the +Android project view (right).
+ + + + + +