How to add Recycler View inside the NestedScrollView which is placed inside a constraint layout, tried to add recycler view but not getting succesful

Question

I am trying to add the RecyclerViewinside the NestedScrollViewwhich is inside a constraint layout,but it not getting add up i.e. RecyclerView is not showing up even after adding it up,please help me,I am adding the XML code of it.

what I am doing

1. Adding the NestedScrollViewinside the constraint layout and adding the RecyclerView below the linear layout which is within the NestedScrollView.

    <layout xmlns:tools="http://schemas.android.com/tools"
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto">
   
        <androidx.constraintlayout.widget.ConstraintLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
   
            tools:context=".ui.MainFragment">
   
            <include
                android:id="@+id/toolbar"
                layout="@layout/toolbar_default_back"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toTopOf="parent" />
   
            <androidx.core.widget.NestedScrollView
                android:id="@+id/scrollview"
                android:layout_width="match_parent"
                android:layout_height="0dp"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintEnd_toEndOf="parent"
   
                android:fillViewport="true"
   
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toBottomOf="@id/toolbar">
   
                <LinearLayout
                    android:id="@+id/linear_layout"
                    android:layout_width="match_parent"
                    android:layout_height="200dp"
                    android:layout_marginStart="20dp"
                    android:layout_marginTop="10dp"
                    android:orientation="horizontal"
                    app:layout_constraintEnd_toEndOf="parent"
                    app:layout_constraintStart_toStartOf="parent"
                    app:layout_constraintTop_toTopOf="parent">
   
                    <ImageView
                        android:id="@+id/imageView13"
                        android:layout_width="wrap_content"
                        android:layout_height="45dp"
                        app:srcCompat="@drawable/ic_baseline_person_add"
                        tools:layout_editor_absoluteX="13dp"
                        tools:layout_editor_absoluteY="14dp" />
   
                    <TextView
                        android:id="@+id/textView42"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_marginStart="10dp"
                        android:layout_marginTop="8dp"
                        android:layout_weight="1"
                        android:text="Received"
                        android:textSize="18sp" />
                </LinearLayout>
   
                <androidx.recyclerview.widget.RecyclerView
                    android:id="@+id/recycler_view"
                    android:layout_width="match_parent"
                    android:layout_height="450dp">
   
   
                </androidx.recyclerview.widget.RecyclerView>
   
            </androidx.core.widget.NestedScrollView>
   
   
        </androidx.constraintlayout.widget.ConstraintLayout>
    </layout>
   

Answer 1

The problem that you have two direct views inside the NestedScrollView, and There should be a single root layout within the `NestedScrollView, and then you can nest any other layout within this root.

To fix your problem, you have to wrap the LinearLayout & the RecyclerView within a root which is arbitrary picked as LinearLayout:

<layout xmlns:tools="http://schemas.android.com/tools"
 xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:app="http://schemas.android.com/apk/res-auto">

 <androidx.constraintlayout.widget.ConstraintLayout
     android:layout_width="match_parent"
     android:layout_height="match_parent"

     tools:context=".ui.MainFragment">

     <include
         android:id="@+id/toolbar"
         layout="@layout/toolbar_default_back"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintTop_toTopOf="parent" />

     <androidx.core.widget.NestedScrollView
         android:id="@+id/scrollview"
         android:layout_width="match_parent"
         android:layout_height="0dp"
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintEnd_toEndOf="parent"
         android:fillViewport="true"
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintTop_toBottomOf="@id/toolbar">


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

             <LinearLayout
                 android:id="@+id/linear_layout"
                 android:layout_width="match_parent"
                 android:layout_height="200dp"
                 android:layout_marginStart="20dp"
                 android:layout_marginTop="10dp"
                 android:orientation="horizontal"
                 app:layout_constraintEnd_toEndOf="parent"
                 app:layout_constraintStart_toStartOf="parent"
                 app:layout_constraintTop_toTopOf="parent">

                 <ImageView
                     android:id="@+id/imageView13"
                     android:layout_width="wrap_content"
                     android:layout_height="45dp"
                     app:srcCompat="@drawable/ic_baseline_person_add"
                     tools:layout_editor_absoluteX="13dp"
                     tools:layout_editor_absoluteY="14dp" />

                 <TextView
                     android:id="@+id/textView42"
                     android:layout_width="wrap_content"
                     android:layout_height="wrap_content"
                     android:layout_marginStart="10dp"
                     android:layout_marginTop="8dp"
                     android:layout_weight="1"
                     android:text="Received"
                     android:textSize="18sp" />
             </LinearLayout>

             <androidx.recyclerview.widget.RecyclerView
                 android:id="@+id/recycler_view"
                 android:layout_width="match_parent"
                 android:layout_height="450dp"/>

        </LinearLayout>

     </androidx.core.widget.NestedScrollView>


 </androidx.constraintlayout.widget.ConstraintLayout>
</layout>