问使用robolectric获取找不到资源的异常

EN

//Service class
MyService extends Service {

private SoundPool mSoundPool;
private int mSoundID;

@Override
public void onCreate(){

mSoundPool = new SoundPool(1, AudioManager.STREAM_MUSIC, 0);
mSoundPool.setOnLoadCompleteListener(new OnLoadCompleteListener() {
    @Override
    public void onLoadComplete(final SoundPool soundPool, final int sampleId,
            final int status) {
        mIsSoundLoaded = true;
    }
});
    //Here I am initializing soundpool and getting resource not found exception
    // It should be context of CustomRobolectricTestRunner 
    mSoundID = mSoundPool.load(getApplicationContext(),R.raw.btn_click, 1);

}

}

 @RunWith(CustomRobolectricTestRunner.class)
//@RunWith(RobolectricTestRunner.class)
public class MyServiceTest
{

    @Test
    public void testOnCreate()
    {
        // String hello = this.activity.getString(R.string.app_name);
        // assertThat(hello, equalTo("Plus Box"));

        MyService service = new MyService();
        service.onCreate(); // Getting exception Resource not found.

        //To cross check, I have accessed resource in the following way
        //and it working fine. I am able to access resource here.
        /*      int resourceId = Robolectric
                .getShadowApplication()
                .getResources()
                .getIdentifier("btn_click", "raw",
                        Robolectric.getShadowApplication().getPackageName());
        if (resourceId != 0)
        {
            // Raw folder contains resource.
            System.out.println("The value of Raw ID " + resourceId);
            assertTrue(true);
        }
        else
        {
            // Raw folder doesn't contain resource.
            System.out.println("The value of Raw ID " + resourceId);
            assertTrue(false);
        }
    */


    }


}

public class TestApplication extends MyApplication {

    @Override
    public void onCreate() {

        createSession(UserGroup.Unknown, 0, SessionState.Active, "", 0, "");


    }

}

public class CustomRobolectricTestRunner extends RobolectricTestRunner
        implements TestLifecycle<Application> {


    public CustomRobolectricTestRunner(final Class<?> testClass)
            throws InitializationError {
        super(testClass);
    }

    @Override
    public void afterTest(Method arg0) {
        // TODO Auto-generated method stub

    }

    @Override
    public void beforeTest(Method arg0) {
        // TODO Auto-generated method stub

    }

    @Override
    public Application createApplication(Method arg0, AndroidManifest manifest) {

        TestApplication testApplication = new TestApplication();
        ShadowContextWrapper shadowApp = Robolectric.shadowOf( testApplication );
        shadowApp.setPackageName("com.example.robolectric");
        testApplication.onCreate();

        return testApplication;
    }

    @Override
    public void prepareTest(Object arg0) {
        // TODO Auto-generated method stub

    }

}