父 RecyclerView 中的子 RecyclerView 显示在父 RecyclerView 的末尾？

Question

Child RecyclerView inside Parent RecyclerView is showing at End of Parent RecyclerView?

I Want To Show Categroy in Parent RecyclerView & show its Sub Category in Child RecyclerView But When I Click Parent RecyclerView To Show That Sub Category the Child RecyclerView is showing at The Full End Of Parent Category Please Check Where Is I'm Wrong?

Here is My Results: First Item Clicked

. Second Item Clicked

My Code:

This Is My Main Layout:

    <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".USER.Category">

    <androidx.recyclerview.widget.RecyclerView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/Category"/>


</LinearLayout>

This is my Main java File:

   public class Category extends AppCompatActivity {
    static Toast Toasts;
    RecyclerView  Category;

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

        Category = findViewById(R.id.Category);
        Category.setLayoutManager(new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false));
        Category_View_request();

    }

    public void Category_View_request() {

        RequestQueue requestQueue = Volley.newRequestQueue(Category.this);
        String url = Constant.Category;
        StringRequest stringRequest = new StringRequest(Request.Method.POST, url, new Response.Listener<String>() {
            @Override
            public void onResponse(String response) {
                GsonBuilder gsonBuilder = new GsonBuilder();
                Gson gson = gsonBuilder.create();
                GridView_listItems[] Category_View_response = gson.fromJson(response, GridView_listItems[].class);
                Category.setAdapter(new CategoryView_Adapter(Category.this, Category_View_response));

            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                Toasts = Toast.makeText(Category.this, "ERROR: Please Check Internet & Try Again", Toast.LENGTH_SHORT);
                Toasts.show();
            }
        });
        requestQueue.add(stringRequest);
    }
}

this is Parent Layout:

    <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_gravity="center"
    android:orientation="vertical"
    android:padding="5dp"
    android:id="@+id/layout">

<androidx.cardview.widget.CardView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="120dp"
        android:id="@+id/nameLayout">

        <ImageView
            android:id="@+id/categoryimage"
            android:layout_width="120dp"
            android:layout_height="120dp"
            android:adjustViewBounds="true"
            android:background="#fff"
            android:contentDescription="@string/todo"
            android:padding="8dp"
            android:scaleType="fitXY" />

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:gravity="center"
            android:orientation="horizontal"
            android:paddingLeft="8dp"
            android:paddingTop="8dp"
            android:paddingRight="8dp"
            android:paddingBottom="8dp">

            <Space
                android:layout_width="112dp"
                android:layout_height="wrap_content" />

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:gravity="center"
                android:orientation="vertical"
                android:paddingLeft="8dp"
                android:paddingTop="8dp"
                android:paddingRight="8dp"
                android:paddingBottom="8dp">

                <TextView
                    android:id="@+id/categoryname"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:paddingStart="1dp"
                    android:singleLine="true"
                    android:text="@string/test_product_name"
                    android:textColor="@color/Black"
                    android:textSize="13sp"
                    tools:ignore="RtlSymmetry" />


                <TextView
                    android:id="@+id/categorydec"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:paddingStart="1dp"
                    android:paddingTop="3dp"
                    android:singleLine="true"
                    android:text="@string/test_product_description"
                    android:textColor="@color/common_google_signin_btn_text_light_default"
                    android:textSize="12sp"
                    tools:ignore="RtlSymmetry" />

            </LinearLayout>
        </LinearLayout>

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/click">
                             </RelativeLayout>

    </RelativeLayout>

    <androidx.cardview.widget.CardView
        android:id="@+id/subview"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_margin="5dp"
        android:background="@color/White"
        android:elevation="8dp"
        android:paddingTop="10dp"
        >

        <androidx.recyclerview.widget.RecyclerView
            android:id="@+id/subCatview"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"/>

    </androidx.cardview.widget.CardView>

    </LinearLayout>
</androidx.cardview.widget.CardView>

</LinearLayout>

This is Parent Adapter:

public class CategoryView_Adapter extends RecyclerView.Adapter<CategoryView_Adapter.CategoryViewHolder> {
    Toast Toasts;
    private static Context context;
    private static GridView_listItems[] data;

    public CategoryView_Adapter(Context context, GridView_listItems[] data) {
        this.context = context;
        this.data = data;
    }

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

    @SuppressLint("SetTextI18n")
    @Override
    public void onBindViewHolder(@NonNull final CategoryViewHolder holder, int position) {
        final GridView_listItems CategoryList = data[position];

        holder.categoryname.setText(CategoryList.getName());
        holder.categorydec.setText(CategoryList.getId());
        Glide.with(holder.categoryimage.getContext())
                .applyDefaultRequestOptions(new RequestOptions()
                        .placeholder(R.drawable.product_loading)
                        .error(R.drawable.product_loading_failed))
                .load(Constant.MAINImagUrl + CategoryList.getCategoryLogo().substring(2))
                .into(holder.categoryimage);
        holder.categoryname.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                holder.layout.setBackgroundColor(ContextCompat.getColor(context, R.color.common_google_signin_btn_text_light_default));

                Grid_View_request(CategoryList.getName());
            }
        });


    }

    @Override
    public int getItemCount() {
        return data.length;
    }

    public static class CategoryViewHolder extends RecyclerView.ViewHolder {
        ImageView categoryimage;
        TextView categoryname, categorydec;
        CardView subview;
        RelativeLayout click;
        LinearLayout layout;
        public static RecyclerView subCatview;

        public CategoryViewHolder(@NonNull View itemView) {
            super(itemView);
            categoryimage = (ImageView) itemView.findViewById(R.id.categoryimage);
            categoryname = (TextView) itemView.findViewById(R.id.categoryname);
            categorydec = (TextView) itemView.findViewById(R.id.categorydec);
            click = (RelativeLayout) itemView.findViewById(R.id.click);
            subview = (CardView) itemView.findViewById(R.id.subview);
            layout = (LinearLayout) itemView.findViewById(R.id.layout);
            subCatview = (RecyclerView) itemView.findViewById(R.id.subCatview);

            GridLayoutManager gridLayoutManager = new GridLayoutManager(MyApplication.getAppContext(), 3, GridLayoutManager.VERTICAL, false);
            subCatview.setLayoutManager(gridLayoutManager);


        }
    }


    public static void Grid_View_request(final String category) {

        RequestQueue requestQueue = Volley.newRequestQueue(MyApplication.getAppContext());
        String url = Constant.Sub_Category;
        StringRequest stringRequest = new StringRequest(Request.Method.POST, url, new Response.Listener<String>() {
            @Override
            public void onResponse(String response) {
                if (response.contains("CityGroceryEmptyResponse")) {
                     Toast.makeText(MyApplication.getAppContext(), "No Sub Category Found", Toast.LENGTH_SHORT).show();
                } else {
                    GsonBuilder gsonBuilder = new GsonBuilder();
                    Gson gson = gsonBuilder.create();
                    Sub_Category_list[] Sub_Category_list = gson.fromJson(response, Sub_Category_list[].class);
                    subCatview.setAdapter(new Sub_Category_Adapter(MyApplication.getAppContext(), Sub_Category_list));
                }

            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
        Toast.makeText(MyApplication.getAppContext(), "ERROR: Please Check Internet & Try Again", Toast.LENGTH_SHORT).show();
            }
        }) {
            @Override
            protected Map<String, String> getParams() {
                Map<String, String> params = new HashMap<String, String>();
                params.put("category", category);
                return params;
            }

            @Override
            public Map<String, String> getHeaders() throws AuthFailureError {
                Map<String, String> params = new HashMap<String, String>();
                params.put("Content-Type", "application/x-www-form-urlencoded");
                return params;
            }
        };
        requestQueue.add(stringRequest);

    }


}

This is My Child Layout:

<androidx.cardview.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="120dp"
    android:layout_gravity="center"
    android:layout_margin="2dp"
    android:orientation="horizontal"
    android:elevation="8dp"
    app:cardCornerRadius="1dp">


    <androidx.constraintlayout.widget.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_gravity="center"
        android:paddingLeft="8dp"
        android:paddingTop="8dp"
        android:paddingRight="8dp"
        android:paddingBottom="8dp">


        <ImageView
            android:id="@+id/subCatNameimage"
            android:layout_width="80dp"
            android:layout_height="80dp"
            android:layout_alignParentStart="true"
            android:layout_alignParentTop="true"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            app:srcCompat="@mipmap/ic_launcher" />

        <TextView
            android:id="@+id/subCatName"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@+id/subCatNameimage"
            android:layout_marginTop="4dp"
            android:gravity="center"
            android:maxLength="30"
            android:text="menu name"
            android:textColor="@color/colorPrimary"
            android:textSize="14sp"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@+id/subCatNameimage" />

    </androidx.constraintlayout.widget.ConstraintLayout>
</androidx.cardview.widget.CardView>

This is My Child Adapter:

public class Sub_Category_Adapter extends RecyclerView.Adapter<Sub_Category_Adapter.CategoryViewHolder> {
    Toast Toasts;
    private static Context context;
    private static Sub_Category_list[] data;



    public Sub_Category_Adapter(Context context, Sub_Category_list[] data) {
        this.context = context;
        this.data = data;
        final Sub_Category_list SubCategoryList = data[0];

    }

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


    @Override
    public void onBindViewHolder(@NonNull final CategoryViewHolder holder, final int position) {
        final Sub_Category_list SubCategoryList = data[position];

        holder.subCatName.setText(SubCategoryList.getSubCategoryName());
        Glide.with(holder.subCatNameimage.getContext())
                .applyDefaultRequestOptions(new RequestOptions()
                        .placeholder(R.drawable.product_loading)
                        .error(R.drawable.product_loading_failed))
                .load(Constant.MAINImagUrl + SubCategoryList.getSubCategoryLogo().substring(2))
                .into(holder.subCatNameimage);


    }

    @Override
    public int getItemCount() {
        return data.length;
    }

    public static class CategoryViewHolder extends RecyclerView.ViewHolder {
        ImageView subCatNameimage;
        TextView subCatName;


        public CategoryViewHolder(@NonNull View itemView) {
            super(itemView);
            subCatName = (TextView) itemView.findViewById(R.id.subCatName);
            subCatNameimage = (ImageView) itemView.findViewById(R.id.subCatNameimage);


        }
    }


}

Please Correct Me Where is doing Mistake

Thanks In Advance

Answer 1

You can achieve that requirement by using an expandable recycler view. There are a lot of libraries you can use to achieve this. You can use this library .

Or follow this post to achieve this on your own, you might need to make some changes to get the output as per your requirement.

Answer 2

I'am achieve My requirement by using an expandable recycler view

HERE