使用视图寻呼机返回null值的字段？

Question

我正在尝试为viewpager创建一个适配器并在适配器中传递一些数据但我的字段返回空值。

CarFragment.java

private static final String CAR_NAME = "car_name";
private static final String CAR_DESCRIPTION = "car_description";

private String mCarName;
private String mDescription;

public static CarFragment newInstance(String carName, String description){
    CarFragment fragment = new CarFragment();
    Bundle args = new Bundle();
    args.putString(CAR_NAME, carName);
    args.putString(CAR_DESCRIPTION, description);
    fragment.setArguments(args);
    return fragment;
}

public CarFragment(){

}

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    Bundle args = getArguments();
    if(args != null){
        mCarName = args.getString(CAR_NAME);
        mDescription = args.getString(CAR_DESCRIPTION);

    }
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View v = inflater.inflate(R.layout.car_tour, container, false);

    TextView carField = (TextView)v.findViewById(R.id.car_name);
    TextView carDescription = (TextView)v.findViewById(R.id.car_description);
    carField.setText("Naam : " + mCarName);
    carDescription.setText("Beschcrijving : " + mDescription);

    return v;
}

我认为错误来自我的适配器。这是获取数据的地方。

我有两个viewpager的案例。有两页。在第一个我想显示对象（0）和另一个对象（1）。 viewpager正在运行，应用程序不会崩溃。但是，似乎我的数据流不正确。在carfragment中它应该显示我从JSONobject中获取的数据。

JSONObject data;
JSONArray car;

public String carName ;
public String description ;

public String CAR_NAAM;
public String CAR_DESCRIPTION;

public CarAdapter(FragmentManager fm) {
    super(fm);
}

public void onEvent(CarResponse reponse) throws JSONException {
    data = reponse.getData();
    car = data.getJSONArray("carList");

    JSONObject firstCar =  car.getJSONObject(0);
    CAR_NAAM = firstCar.getString("name");
    CAR_DESCRIPTION = firstCar.getString("description");

}

@Override
public Fragment getItem(int position) {

    switch (position){
        case 0:
            coffeeName = CAR_NAAM;
            description = CAR_DESCRIPTION;


        case 1:
            carName = CAR_NAAM;
            description = CAR_DESCRIPTION;

    }
    return CarFragment.newInstance(carName, description);
}

我希望问题很清楚，你可以提供帮助。如果需要更多细节，请随时询问。