Avoid passing null as the view root (need to resolve layout parameters on the inflated layout's root element)

Question

Passing null for root studio gives me this warning:

Avoid passing null as the view root (need to resolve layout parameters on the inflated layout's root element)

It is showing a null value in getGroupView. Please help.

public class ExpandableListAdapter extends BaseExpandableListAdapter {      private Context _context;     private List<String> _listDataHeader; // header titles     // child data in format of header title, child title     private HashMap<String, List<String>> _listDataChild;      public ExpandableListAdapter(Context context, List<String> listDataHeader,                                  HashMap<String, List<String>> listChildData) {         super();         this._context = context;         this._listDataHeader = listDataHeader;         this._listDataChild = listChildData;     }      @Override     public Object getChild(int groupPosition, int childPosititon) {         return this._listDataChild.get(this._listDataHeader.get(groupPosition))                 .get(childPosititon);     }      @Override     public long getChildId(int groupPosition, int childPosition) {         return childPosition;     }      @Override     public View getChildView(int groupPosition, final int childPosition,                              boolean isLastChild, View convertView, ViewGroup parent) {          final String childText = (String) getChild(groupPosition, childPosition);          if (convertView == null) {             LayoutInflater infalInflater = (LayoutInflater) this._context                     .getSystemService(Context.LAYOUT_INFLATER_SERVICE);             convertView = infalInflater.inflate(R.layout.list_item, null);           }          TextView txtListChild = (TextView) convertView                 .findViewById(R.id.lblListItem);          txtListChild.setText(childText);         return convertView;     }      @Override     public int getChildrenCount(int groupPosition) {         return this._listDataChild.get(this._listDataHeader.get(groupPosition))                 .size();     }      @Override     public Object getGroup(int groupPosition) {         return this._listDataHeader.get(groupPosition);     }      @Override     public int getGroupCount() {         return this._listDataHeader.size();     }      @Override     public long getGroupId(int groupPosition) {         return groupPosition;     }      @Override     public View getGroupView(int groupPosition, boolean isExpanded,                              View convertView, ViewGroup parent) {         String headerTitle = (String) getGroup(groupPosition);         if (convertView == null) {             LayoutInflater infalInflater = (LayoutInflater) this._context                     .getSystemService(Context.LAYOUT_INFLATER_SERVICE);             convertView = infalInflater.inflate(R.layout.list_group, null);         }          TextView lblListHeader = (TextView) convertView                 .findViewById(R.id.lblListHeader);         lblListHeader.setTypeface(null, Typeface.BOLD);         lblListHeader.setText(headerTitle);          return convertView;     }      @Override     public boolean hasStableIds() {         return false;     }      @Override     public boolean isChildSelectable(int groupPosition, int childPosition) {         return true;     }  } 

Answer 1

Instead of doing

convertView = infalInflater.inflate(R.layout.list_item, null); 

do

convertView = infalInflater.inflate(R.layout.list_item, parent, false); 

It will inflate it with the given parent, but won't attach it to the parent.