Android : Parcelable을 Activity에서 Fragment로 확장하는 Custom POJO의 ArrayList 전달

Question

Parcelable을 Bundle로 내 Activity에서 Fragment로 확장하는 사용자 정의 POJO를 전달하려고합니다. 채워진 번들 객체는 내 Fragment의 newInstance 메소드에 성공적으로 전달됩니다. 그러나 내 Fragment의 onCreate 메서드에서이 POJO 클래스의 ArrayList를 복구하려고하면 어떻게 든 삭제됩니다.

//Activity 
protected void onCreate(@Nullable Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_recipe_detail); 

    mRecipe = getIntent().getParcelableExtra("com.wernerraubenheimer.bakingapp.data.RecipeModel"); 
//This works mRecipe is successfully populated with my custom ArrayList<IngredientModel> 
//My class IngredientModel extends Parcelable 

    IngredientListFragment ingredientListFragment = IngredientListFragment.newInstance(mRecipe.getIngredients()); 
//Still good so far.... 

    getSupportFragmentManager() 
      .beginTransaction() 
      .add(R.id.first_fragment_container, new IngredientListFragment()) 
      .commit(); 
} 

//Fragment 
public static IngredientListFragment newInstance(ArrayList<IngredientModel> ingredients) { 

    IngredientListFragment ingredientListFragment = new IngredientListFragment(); 
    Bundle bundle = new Bundle(); 
    bundle.putParcelableArrayList("ingredients", ingredients); 
    ingredientListFragment.setArguments(bundle); 

    return ingredientListFragment; 
} 

@Override 
public void onCreate(@Nullable Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
//This is where the ball gets dropped, mIngredientList which I initialized when I declared it just after 
//class declaration: private ArrayList<IngredientModel> mIngredientList = new ArrayList<>(); 
//is now empty?? 
//I have also placed the call to super.onCreate after the statement below 
    mIngredientList = getArguments().getParcelableArrayList("ingredients"); 
    //have also used savedInstanceState 
} 

나는 나의 조각의 onCreateView에 RecyclerView에 ArrayList를 사용하려는 :

public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) { 

    View rootView = inflater.inflate(R.layout.fragment_ingredient_list, container, false); 

    rvIngredientList = (RecyclerView)rootView.findViewById(R.id.rv_ingredient_list); 
    ingredientLayoutManager = new LinearLayoutManager(getActivity()); 
    ingredientLayoutManager.setOrientation(LinearLayoutManager.VERTICAL); 
    rvIngredientList.setLayoutManager(ingredientLayoutManager); 

    IngredientListAdapter ingredientListAdapter = new IngredientListAdapter(mIngredientList); 
    rvIngredientList.setAdapter(ingredientListAdapter); 

    return rootView; 
} 

Answer 1

사용자가 만든 객체를 사용하고 있는지 확인하십시오.

이렇게하면됩니다.

IngredientListFragment ingredientListFragment = IngredientListFragment.newInstance(mRecipe.getIngredients()); 

getSupportFragmentManager() 
     .beginTransaction() 
     .add(R.id.first_fragment_container, ingredientListFragment) 
     .commit(); 

Answer 2

getSupportFragmentManager() 
      .beginTransaction() 
      .add(R.id.first_fragment_container, new 
      IngredientListFragment()) 
      .commit(); 

in this method you are providing new instance of fragment, rather than the one which you created using 
IngredientListFragment ingredientListFragment = IngredientListFragment.newInstance(mRecipe.getIngredients());