How you setup the Android Support Libraries in your development project depends on what features you want to use and what range of Android platform versions you want to support with your application.
This document guides you through downloading the Support Library package and adding libraries to your development environment.
The Android Support Library package is provided as a supplemental download to the Android SDK and is available through the Android SDK Manager. Follow the instructions below to obtain the Support Library files.
To download the Support Library through the SDK Manager:
Note: If you're developing with Android Studio, select and install the Android Support Repository item instead.
Figure 1. The Android SDK Manager with the Android Support Library selected.
After downloading, the tool installs the Support Library files to your existing Android SDK directory. The library files are located in the following subdirectory of your SDK: {@code <sdk>/extras/android/support/} directory.
Before adding a Support Library to your application, decide what features you want to include and the lowest Android versions you want to support. For more information on the features provided by the different libraries, see Support Library Features.
In order to use a Support Library, you must modify your application's project's classpath dependencies within your development environment. You must perform this procedure for each Support Library you want to use.
Some Support Libraries contain resources beyond compiled code classes, such as images or XML files. For example, the v7 appcompat and v7 gridlayout libraries include resources.
If you are not sure if a library contains resources, check the Support Library Features page. The following sections describe how to add a Support Library with or without resources to your application project.
To add a Support Library without resources to your application project:
dependencies {
...
compile "com.android.support:support-v4:18.0.+"
}
To add a Support Library with resources (such as v7 appcompat for action bar) to your application project:
dependencies {
...
compile "com.android.support:appcompat-v7:18.0.+"
}
Support Library classes that provide support for existing framework APIs typically have the
same name as framework class but are located in the android.support class packages,
or have a *Compat suffix.
Caution: When using classes from the Support Library, be certain you import the class from the appropriate package. For example, when applying the {@code ActionBar} class:
Note: After including the Support Library in your application project, we strongly recommend using the ProGuard tool to prepare your application APK for release. In addition to protecting your source code, the ProGuard tool also removes unused classes from any libraries you include in your application, which keeps the download size of your application as small as possible. For more information, see ProGuard.
Further guidance for using some Support Library features is provided in the Android developer training classes, guides and samples. For more information about the individual Support Library classes and methods, see the {@link android.support.v4.app android.support} packages in the API reference.
If you are increasing the backward compatibility of your existing application to an earlier
version of the Android API with the Support Library, make sure to update your application's
manifest. Specifically, you should update the android:minSdkVersion
element of the
<uses-sdk> tag in the manifest to the new, lower version number, as
shown below:
<uses-sdk
android:minSdkVersion="7"
android:targetSdkVersion="17" />
The manifest setting tells Google Play that your application can be installed on devices with Android 2.1 (API level 7) and higher.
If you are using Gradle build files, the minSdkVersion setting in the build file
overrides the manifest settings.
apply plugin: 'com.android.application'
android {
...
defaultConfig {
minSdkVersion 8
...
}
...
}
In this case, the build file setting tells Google Play that the default build variant of your application can be installed on devices with Android 2.2 (API level 8) and higher. For more information about build variants, see Build System Overview.
Note: If you are including the v4 support and v7 appcompat libraries in your
application, you should specify a minimum SDK version of "7" (and not
"4"). The highest support library level you include in your application determines
the lowest API version in which it can operate.
Each Support Library includes code samples to help you get started using the support APIs. The code is included in the download from the SDK Manager and is placed inside the Android SDK installation directory, as listed below: