Copy-pasting the code snippets provided in the article may work, but sometimes you might need to also put in place some very basic code adjustments; 

the intent of the articles like the one you refer to is to guide you and provide some help, not necessarily to enable you to blindly copy-oaste the code.... understanding what you copy and paste is always preferrable rather than just doing it blindly.

AlessandroB  really appreciated , I am new here , can I ask one more question?

accourding to this article 

https://developer.vuforia.com/resources/dev-guide/textured-plane-target

how to  replace the OpenGL ES 2.0 rendering code in the renderFrame method with the following?

JNIEXPORT void JNICALL

You re welcome

thank you very much !!

Please see this page:

https://developer.vuforia.com/resources/dev-guide/step-3-compiling-running-vuforia-sample-app

dear AlessandroB:

thanks for your advise, but I still encounter this problem,  I already use Cygwin to ndk-build , so how to use ndk-build to build the native sample code? because I search for a long day, I still can't find, pleasy answer for me , thank you very much 

this is my erro message

04-14 00:27:41.123: E/AndroidRuntime(19439): at com.qualcomm.QCARSamples.Dominoes.Dominoes.setActivityPortraitMode(Native Method)

Hi, sorry, but the Dominoes sample (even in the latest SDK) is based on the C++ API of Vuforia.

Of course, the backbones of the sample are still in Java (and there is some "wrapping" Java API used), but most of the relevant Vuforia code is the C++ code contained in the "jni" sub-folder of the sample project. Please check the jni folder.

The Java API is oonl used for linking /wrapping the C++ part into the Android application.

So, you need to:

- use ndk-build to build the native sample code

- refresh your project in Eclipse

- clean the project (this can help sometimes) in Eclipse

- build and run from Eclipse

Also, if you check the Logs with ADB or Eclipse, you should be able to see the exact error messages (the "Unfortunately Dominoes has stopped" message is just the Toast message shown by Android on the device screen, but this is not telling much on the actual error).

I'm not trying to build native app. Dominoes sample is based on Java API. And this solution is not working:

NOTE: If you get an error at application startup, such as “Application has stopped unexpectedly”, and if you are using Android SDK Tools r17 (or above), you may need to execute the following steps in Eclipse:

1. Right-click the project, and select Properties > Java Build Path > Order and Export.
2. Activate the checkbox next to the Vuforia JAR file.
3. Close the project properties.
4. Clean and rebuild the project.

This is probbly because you did not compile the native C++ part of the sample project, using NDK-build; please read the developer guide on how to install and build the samples:

https://developer.vuforia.com/resources/sdk/android

and this:

https://developer.vuforia.com/forum/faq/android-how-do-i-fix-my-compile-or-runtime-errors