Getting Started with the NDK

This document explains how to:

• Get and install the NDK.
• Configure your system and the Eclipse and the Android Development Tools (“ADT”) for use with it.
• Verify, using a simple sample, that everything is working as expected.

Note that this document assumes that you are already familiar with Java-based Android development. For more information on that topic, see the Android developer site.

Installation

To install and configure the NDK, follow the steps below:

1. To use the NDK, you must first have the Android SDK installed.
2. Next, download and unzip the NDK, making sure to download the correct version for your development platform. You may place the unzipped directory anywhere on your local drive.
3. If you are building from the command line, open a terminal window, and update your PATH environment variable with the location of the directory that contains the NDK.

• For example, in bash:

• export PATH=$PATH:~/Android_SDK/NDK/
  

• Or, in Windows:

• set PATH=%PATH%;C:/Android_SDK/NDK/android-ndk-r10
  

Configuring Eclipse

Eclipse must know where the NDK is in order to use it when building your app.Follow these steps to set the location of the NDK:

1. Launch Eclipse, which is installed as part of the Android SDK.
2. Open Preferences.
3. In the pane on the left side of the Preferences window, select Android > NDK. The Android section expands, revealing a number of subsections.
4. Select NDK. In the pane on the right side of the Preferences window, browse to the directory that contains the NDK.
5. Click OK to return to the Package Explorer display.

Verification

Eclipse

To confirm that you have installed the NDK, set it up correctly, and properly configure Eclipse, follow these steps:

1. Import the hello-jni sample from `<ndk>/samples/’, as you would any other Android project.
2. In the Project Explorer pane, right-click the project name (HelloJni). A context menu appears.
3. From the context menu, select Android Tools > Add Native Support, as shown in Figure 2. The Add Android Native Support window appears.


Figure 1. Adding native support to your project

4. Accept the default library name (“hello-jni”), and click Finish.
5. Build and execute the application.

Command line

Follow these steps to build from the command line:

1. Change to the root directory of your project.
2. Execute ndk-build to build the native component of your app.
   

$ ndk-build

3. Build and install your project as you would a regular Android app written in Java. For more information, see Building and Running and Building and Running from the Command Line.

If you have successfully installed and configured the NDK, the screen on your target device looks as shown in Figure 3.

Figure 2. Target-device screen after successful launch