具有列表的发送意图具有列表

Question

我目前正在努力发送一个包含列表的Object的意图。基本上，我可以将正确的数据发送到另一个活动，但是我无法在数据中获取列表。抱歉，我真的不知道该如何形容。

事实是，我可以通过调用例如在RecipeActivity中获取配料recipes.get(0).getIngredients()，但是在RecipeDetailsActivity中，由于列表为空，因此出现错误。 （而且我也不知道如何在DetailsActivity中获得对象的正确索引）

提前感谢！

Recipe.java

public class Recipe implements Parcelable {
@SerializedName("id")
@Expose
private Integer mId;
@SerializedName("name")
@Expose
private String mName;
@SerializedName("ingredients")
@Expose
private List<Ingredient> mIngredients = null;
@SerializedName("steps")
@Expose
private List<Step> mSteps = null;
@SerializedName("servings")
@Expose
private Integer mServings;
@SerializedName("image")
@Expose
private String mImage;

protected Recipe(Parcel in) {
    if (in.readByte() == 0) {
        mId = null;
    } else {
        mId = in.readInt();
    }
    mName = in.readString();
    if (in.readByte() == 0) {
        mServings = null;
    } else {
        mServings = in.readInt();
    }
    mImage = in.readString();
}

public static final Creator<Recipe> CREATOR = new Creator<Recipe>() {
    @Override
    public Recipe createFromParcel(Parcel in) {
        return new Recipe(in);
    }

    @Override
    public Recipe[] newArray(int size) {
        return new Recipe[size];
    }
};

public Integer getId() {
    return mId;
}

public void setId(Integer id) {
    mId = id;
}

public String getName() {
    return mName;
}

public void setName(String name) {
    mName = name;
}

public List<Ingredient> getIngredients() {
    return mIngredients;
}

public void setIngredients(List<Ingredient> ingredients) {
    mIngredients = ingredients;
}

public List<Step> getSteps() {
    return mSteps;
}

public void setSteps(List<Step> steps) {
    mSteps = steps;
}

public Integer getServings() {
    return mServings;
}

public void setServings(Integer servings) {
    mServings = servings;
}

public String getImage() {
    return mImage;
}

public void setImage(String image) {
    mImage = image;
}

@Override
public int describeContents() {
    return 0;
}

@Override
public void writeToParcel(Parcel dest, int flags) {
    if (mId == null) {
        dest.writeByte((byte) 0);
    } else {
        dest.writeByte((byte) 1);
        dest.writeInt(mId);
    }
    dest.writeString(mName);
    if (mServings == null) {
        dest.writeByte((byte) 0);
    } else {
        dest.writeByte((byte) 1);
        dest.writeInt(mServings);
    }
    dest.writeString(mImage);
}

}

Ingredient.java

public class Ingredient {

@SerializedName("quantity")
@Expose
private Double mQuantity;
@SerializedName("measure")
@Expose
private String mMeasure;
@SerializedName("ingredient")
@Expose
private String mIngredient;

public Double getQuantity() {
    return mQuantity;
}

public void setQuantity(Double quantity) {
    mQuantity = quantity;
}

public String getMeasure() {
    return mMeasure;
}

public void setMeasure(String measure) {
    mMeasure = measure;
}

public String getIngredient() {
    return mIngredient;
}

public void setIngredient(String ingredient) {
    mIngredient = ingredient;
}

}

RecipeActivity

public class RecipeActivity extends AppCompatActivity implements RecipeAdapter.RecipeAdapterOnClickHandler{
private static final String TAG = RecipeActivity.class.getSimpleName();

@BindView(R.id.recipe_recycler_view)
RecyclerView mRecyclerView;

private RecipeAdapter mRecipeAdapter;
private List<Recipe> recipes;

public static final String MY_RECIPE = "myRecipe";

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_recipe);

    RecipeService service = RecipeClient.getRetrofit().create(RecipeService.class);

    Call<List<Recipe>> call = service.getAllRecipes();
    call.enqueue(new Callback<List<Recipe>>() {
        @Override
        public void onResponse(Call<List<Recipe>> call, Response<List<Recipe>> response) {
            if (response.isSuccessful()) {
                recipes = response.body();
                generateDataList(recipes);
            }
        }

        @Override
        public void onFailure(Call<List<Recipe>> call, Throwable t) {
            Toast.makeText(RecipeActivity.this, "Something went wrong...Please try later!", Toast.LENGTH_SHORT).show();
            Log.v(TAG, t.toString());
        }
    });
}

private void generateDataList(List<Recipe> recipeList) {
    ButterKnife.bind(this);
    mRecipeAdapter = new RecipeAdapter(this, recipeList, RecipeActivity.this);
    RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(RecipeActivity.this);
    mRecyclerView.setLayoutManager(layoutManager);
    mRecyclerView.setAdapter(mRecipeAdapter);
}


@Override
public void onClick(int adapterPosition) {
    Context context = this;
    Class detailClass = RecipeDetailsActivity.class;

    Intent detailsIntent = new Intent(context, detailClass);
    detailsIntent.putExtra(MY_RECIPE, recipes.get(adapterPosition));
    startActivity(detailsIntent);
}

}

RecipeDetailsActivity

public class RecipeDetailsActivity extends AppCompatActivity implements IngredientAdapter.IngredientAdapterOnClickHandler{
private static final String TAG = RecipeDetailsActivity.class.getSimpleName();

private Recipe recipes;
private List<Recipe> recipeList;

private String recipeName;
private String ingredient;
private Double quantity;
private String measure;
private List<Ingredient> ingredientList = new ArrayList<>();
IngredientAdapter mAdapter;

@Nullable
@BindView(R.id.ingredients)
TextView ingredientsTV;
@Nullable
@BindView(R.id.quantity)
TextView quantityTV;
@BindView(R.id. recipe_details_rv)
RecyclerView mRecyclerView;

@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_recipe_details);

    Intent intentToCatch = getIntent();
    recipes = intentToCatch.getParcelableExtra(RecipeActivity.MY_RECIPE);

    recipeName = recipes.getName();
    ingredientList = recipes.getIngredients();
    if (ingredientList != null) {
        ingredient = ingredientList.get(0).getIngredient();
        quantity = ingredientList.get(0).getQuantity();
        measure = ingredientList.get(0).getMeasure();
    } else {
        Log.v(TAG, "FAILING LOADING INGREDIENTSLIST");
    }
    setTitle(recipeName);

    ButterKnife.bind(this);

    mAdapter = new IngredientAdapter(this, ingredientList, RecipeDetailsActivity.this);
    RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(RecipeDetailsActivity.this);
    mRecyclerView.setLayoutManager(layoutManager);
    mRecyclerView.setAdapter(mAdapter);

}

@Override
public void onClick(int adapterPosition) {

}

}

RecipeAdapter

public class RecipeAdapter extends RecyclerView.Adapter<RecipeAdapter.RecipeAdapterViewHolder> {

private List<Recipe> mRecipeList;
private Context mContext;
private RecipeAdapterOnClickHandler mOnClickHandler;

public RecipeAdapter(Context context, List<Recipe> recipeList, RecipeAdapterOnClickHandler onClickHandler) {
    mContext = context;
    mRecipeList = recipeList;
    mOnClickHandler = onClickHandler;
}

public interface RecipeAdapterOnClickHandler {
    void onClick(int adapterPosition);
}

public class RecipeAdapterViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{
    @BindView(R.id.recipe_name)
    TextView mRecipeName;

    public RecipeAdapterViewHolder(@NonNull View itemView) {
        super(itemView);
        itemView.setOnClickListener(this);
        ButterKnife.bind(this, itemView);
    }

    @Override
    public void onClick(View v) {
        int adapterPosition = getAdapterPosition();
        mOnClickHandler.onClick(adapterPosition);
    }

}

@NonNull
@Override
public RecipeAdapterViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    LayoutInflater layoutInflater = LayoutInflater.from(parent.getContext());
    View view = layoutInflater.inflate(R.layout.recipe_list_item, parent, false);
    return new RecipeAdapterViewHolder(view);
}

@Override
public void onBindViewHolder(@NonNull RecipeAdapterViewHolder holder, int position) {
    holder.mRecipeName.setText(mRecipeList.get(position).getName());
}

@Override
public int getItemCount() {
    if (mRecipeList == null) {
        return 0;
    }
    return mRecipeList.size();
}

}

IngredientAdapter

public class IngredientAdapter extends RecyclerView.Adapter<IngredientAdapter.IngredientAdapterViewHolder> {

private List<Ingredient> mIngredient;
private Context mContext;
private IngredientAdapterOnClickHandler mOnClickHandler;

public IngredientAdapter(Context context, List<Ingredient> ingredientList, IngredientAdapterOnClickHandler onClickHandler) {
    mContext = context;
    mIngredient = ingredientList;
    mOnClickHandler = onClickHandler;
}

public interface IngredientAdapterOnClickHandler {
    void onClick(int adapterPosition);
}

public class IngredientAdapterViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{
    @BindView(R.id.ingredients)
    TextView ingredientTextView;
    @BindView(R.id.step_description)
    TextView stepsDescriptionTextView;
    @BindView(R.id.quantity)
    TextView quantityDescriptionTextView;

    public IngredientAdapterViewHolder(@NonNull View itemView) {
        super(itemView);
        ButterKnife.bind(this, itemView);
    }

    @Override
    public void onClick(View v) {
        int adapterPosition = getAdapterPosition();
        mOnClickHandler.onClick(adapterPosition);
    }
}

@NonNull
@Override
public IngredientAdapterViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    LayoutInflater layoutInflater = LayoutInflater.from(parent.getContext());
    View view = layoutInflater.inflate(R.layout.recipe_details_list_item, parent, false);
    return new IngredientAdapterViewHolder(view);
}

@Override
public void onBindViewHolder(@NonNull IngredientAdapterViewHolder holder, int position) {
    holder.ingredientTextView.setText(mIngredient.get(position).getIngredient());
    holder.stepsDescriptionTextView.setText(mIngredient.get(position).getQuantity().toString());
    holder.quantityDescriptionTextView.setText(mIngredient.get(position).getMeasure());

}

@Override
public int getItemCount() {
    if (mIngredient == null) {
        return 0;
    }
    return mIngredient.size();
}

}

Answer 1

我建议您将Recipe recipes变量放在RecipeDetailsActivity公共静态变量内。像public static Recipe recipes。当您打开“详细”活动时，就像这样：RecipeDetailsActivity.recipes = recipes.get(adapterPosition);在这种情况下，这将是一个更简单的解决方案。