How to have a ListView/RecyclerView inside a parent RecyclerView?

Question

I want to add some child Views (List Items), which come to me from JSON formatted data. Each child list is under a parent list item row. How can I populate it in RecyclerView for each row item (Parent items with child list items)?

I have tried using RecyclerView within RecyclerView parent row (for populating child lists), but here child views are not visible.

Parent Adapter Class

public class DigitizedPrescAdapter extends RecyclerView.Adapter<DigitizedPrescAdapter.ListItemViewHolder>{     private List<PrescriptionModal> prescriptionList;      MedicinesInPrescAdapter adapter;      public DigitizedPrescAdapter(List<PrescriptionModal> prescriptionListModal) {          if (prescriptionListModal == null) {             throw new IllegalArgumentException(                     "PrescriptionList must not be null");         }         this.prescriptionList = prescriptionListModal;     }      @Override     public ListItemViewHolder onCreateViewHolder(             ViewGroup viewGroup, int viewType) {         View itemView = LayoutInflater.                 from(viewGroup.getContext()).                 inflate(R.layout.item_row_digitised_request,                         viewGroup,                         false);         return new ListItemViewHolder(itemView);     }      @Override     public void onBindViewHolder(             ListItemViewHolder viewHolder, int position) {         PrescriptionModal model = prescriptionList.get(position);          viewHolder.prescnum.setText("Prescription "+ ++position);         viewHolder.prescNo.setText("Prescription: "+model.getPrescriptionID());         viewHolder.doctorType.setText("Type: "+model.getDoctorType());         viewHolder.doctorName.setText("Doctor: "+model.getDoctorName());         viewHolder.patientName.setText("Patient: "+model.getPatientName());          adapter = new MedicinesInPrescAdapter(model.getLstproduct());         viewHolder.lstMedicines.setAdapter(adapter);      }      @Override     public int getItemCount() {         return prescriptionList.size();     }      public final static class ListItemViewHolder             extends RecyclerView.ViewHolder {          TextView prescnum;         TextView prescNo;         TextView doctorType;         TextView patientName;         TextView doctorName;         CheckBox selectAll;         RecyclerView lstMedicines;          public ListItemViewHolder(View itemView) {             super(itemView);             prescnum = (TextView) itemView.findViewById(R.id.prescnum);             prescNo = (TextView) itemView.findViewById(R.id.prescNo);             doctorType = (TextView) itemView.findViewById(R.id.doctorType);             patientName = (TextView) itemView.findViewById(R.id.patientName);             doctorName = (TextView) itemView.findViewById(R.id.doctorName);             selectAll = (CheckBox) itemView.findViewById(R.id.selectAll);             lstMedicines = (RecyclerView) itemView.findViewById(R.id.lstAllMedicines);             MyLinearLayoutManager layoutManager = new MyLinearLayoutManager(itemView.getContext(),LinearLayoutManager.VERTICAL,false);             lstMedicines.setHasFixedSize(false);             lstMedicines.setLayoutManager(layoutManager);         }     } } 

Child Adapter Class

public class MedicinesInPrescAdapter extends RecyclerView.Adapter<MedicinesInPrescAdapter.MedicineListItemViewHolder>{      List<Modal_Product_List> prescriptionProducts;      public MedicinesInPrescAdapter(List<Modal_Product_List> prescriptionListProd) {          if (prescriptionListProd == null) {             throw new IllegalArgumentException(                     "PrescriptionProductList must not be null");         }         this.prescriptionProducts = prescriptionListProd;     }      @Override     public MedicineListItemViewHolder onCreateViewHolder(             ViewGroup viewGroup, int viewType) {         View itemView = LayoutInflater.                 from(viewGroup.getContext()).                 inflate(R.layout.item_row_medicine_productlist,                         viewGroup,                         false);         return new MedicineListItemViewHolder(itemView);     }      @Override     public void onBindViewHolder(             MedicineListItemViewHolder viewHolder, int position) {         Modal_Product_List modelMedicine = prescriptionProducts.get(position);          viewHolder.medicineName.setText(modelMedicine.getMedicinename());         viewHolder.medQty.setText(modelMedicine.getQuantity());         viewHolder.days.setText("30");         viewHolder.Amount.setText(modelMedicine.getQuantitybasedprice());     }      @Override     public int getItemCount() {         return prescriptionProducts.size();     }      public final static class MedicineListItemViewHolder             extends RecyclerView.ViewHolder {          TextView medicineName;         EditText medQty;         TextView days;         TextView Amount;         CheckBox selectMe;          public MedicineListItemViewHolder(View itemView) {             super(itemView);             medicineName = (TextView) itemView.findViewById(R.id.medicineName);             medQty = (EditText) itemView.findViewById(R.id.medQty);             days = (TextView) itemView.findViewById(R.id.days);             Amount = (TextView) itemView.findViewById(R.id.amount);             selectMe = (CheckBox) itemView.findViewById(R.id.selectMe);         }     } } 

Answer 1

I got this issue few days ago and finally solved it. All you have to do is @override the layout manager onMeasure function as below:

CustomLinearLayoutManager

public class CustomLinearLayoutManager extends LinearLayoutManager {      private static final String TAG = CustomLinearLayoutManager.class.getSimpleName();      public CustomLinearLayoutManager(Context context) {         super(context);     }      public CustomLinearLayoutManager(Context context, int orientation, boolean reverseLayout) {         super(context, orientation, reverseLayout);     }      private int[] mMeasuredDimension = new int[2];      @Override     public void onMeasure(RecyclerView.Recycler recycler, RecyclerView.State state, int widthSpec, int heightSpec) {          final int widthMode = View.MeasureSpec.getMode(widthSpec);         final int heightMode = View.MeasureSpec.getMode(heightSpec);         final int widthSize = View.MeasureSpec.getSize(widthSpec);         final int heightSize = View.MeasureSpec.getSize(heightSpec);          int width = 0;         int height = 0;         for (int i = 0; i < getItemCount(); i++) {             measureScrapChild(recycler, i, View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED),                 View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED),                 mMeasuredDimension);               if (getOrientation() == HORIZONTAL) {                 width = width + mMeasuredDimension[0];                 if (i == 0) {                     height = mMeasuredDimension[1];                 }             } else {                 height = height + mMeasuredDimension[1];                 if (i == 0) {                     width = mMeasuredDimension[0];                 }             }         }         switch (widthMode) {             case View.MeasureSpec.EXACTLY:                 width = widthSize;             case View.MeasureSpec.AT_MOST:             case View.MeasureSpec.UNSPECIFIED:         }          switch (heightMode) {             case View.MeasureSpec.EXACTLY:                 height = heightSize;             case View.MeasureSpec.AT_MOST:             case View.MeasureSpec.UNSPECIFIED:         }          setMeasuredDimension(width, height);     }      private void measureScrapChild(RecyclerView.Recycler recycler, int position, int widthSpec,                                int heightSpec, int[] measuredDimension) {         try {             View view = recycler.getViewForPosition(0);//fix IndexOutOfBoundsException              if (view != null) {                 RecyclerView.LayoutParams p = (RecyclerView.LayoutParams) view.getLayoutParams();                  int childWidthSpec = ViewGroup.getChildMeasureSpec(widthSpec,                     getPaddingLeft() + getPaddingRight(), p.width);                  int childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec,                     getPaddingTop() + getPaddingBottom(), p.height);                  view.measure(childWidthSpec, childHeightSpec);                 measuredDimension[0] = view.getMeasuredWidth() + p.leftMargin + p.rightMargin;                 measuredDimension[1] = view.getMeasuredHeight() + p.bottomMargin + p.topMargin;                 recycler.recycleView(view);             }         } catch (Exception e) {             e.printStackTrace();         }      } } 

You can just copy and paste the custom layout manager as above and in set up your recyclerview in the parent adapter like this:

RecyclerView.LayoutManager layoutManager = new CustomLinearLayoutManager(mContext); holder.childRecyclerView.setLayoutManager(layoutManager); 

Remember : Don't use same layoutManager as parent adapter, or error will occur.