如果组的孩子计数为零，则 ExpandableListview 会出现 IndexOutOfBoundsException

Question

希望你们一切都好。好吧，我在一个小问题上浪费了将近 2 天（48 小时）。我正在与 expandablelistview 一起工作，我列表的一些组有 children，其余为空没有 children。当列表有 children 时，该列表运行良好，但如果该组没有 children，则应用程序崩溃。

此外，我正在做的事情如下所示。

 public void getCartData(){
    cartProgress.setVisibility(View.VISIBLE);
    listDataHeader = new ArrayList<>();
    ListChild = new ArrayList<>();
    DatabaseReference query = mDatabase;
    query.addListenerForSingleValueEvent(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            //child is each element in the finished list
             td = (HashMap<String, Object>) dataSnapshot.getValue();
            if(td!=null) {

                values = td.values();
                String string = values.toString();

                JSONArray jsonArray = null;
                try {
                    jsonArray = new JSONArray(values);

                    for (int a = 0; a < jsonArray.length(); a++) {

                        JSONObject allJsonObject = jsonArray.getJSONObject(a);

                        CartFragParentModel cartFragParentModel = new CartFragParentModel();

                        cartFragParentModel.setItem_name(allJsonObject.optString("mName"));
                        cartFragParentModel.setItem_price(allJsonObject.optString("mPrice"));
                        mQuantity = allJsonObject.optString("mQuantity");
                        cartFragParentModel.setItem_quantity(allJsonObject.optString("mQuantity"));
                        cartFragParentModel.setItem_symbol(allJsonObject.optString("mCurrency"));

                        listDataHeader.add(cartFragParentModel);
                        listChildData = new ArrayList<>();

                        if (!allJsonObject.has("extraItem")) {
                            cartProgress.setVisibility(View.GONE);
                        }
                        else {
                            JSONArray extraItemArray = allJsonObject.getJSONArray("extraItem");

                            for (int b = 0; b < extraItemArray.length(); b++) {

                                JSONObject jsonObject = extraItemArray.getJSONObject(b);

                                CartFragChildModel cartFragChildModel = new CartFragChildModel();

                                cartFragChildModel.setQuantity(allJsonObject.optString("mQuantity"));
                                cartFragChildModel.setSymbol(allJsonObject.optString("mCurrency"));
                                cartFragChildModel.setName(jsonObject.optString("menu_extra_item_name"));
                                cartFragChildModel.setPrice(jsonObject.optString("menu_extra_item_price"));

                                listChildData.add(cartFragChildModel);
                            }
                            ListChild.add(listChildData);

                        }

                        cartFragExpandable = new CartFragExpandable(getContext(), listDataHeader, ListChild);
                        selected_item_list.setAdapter(cartFragExpandable);
                        cartProgress.setVisibility(View.GONE);
                        int itemCount = cartFragExpandable.getGroupCount();

                        for(int i=0; i < cartFragExpandable.getGroupCount(); i++)
                                    try {
                                        selected_item_list.expandGroup(i);
                                    }catch (IndexOutOfBoundsException e){
                                        e.getCause();
                                    }




                    }

                } catch (JSONException e) {
                    e.printStackTrace();
                }
            }
            else {
                cartProgress.setVisibility(View.GONE);
                no_cart_div.setVisibility(View.VISIBLE);
            }
        }

        @Override
        public void onCancelled(DatabaseError databaseError) {

        }
    });

}

另外，我得到自定义适配器的异常

ublic class CartFragExpandable  extends BaseExpandableListAdapter {

Context context;
ArrayList<CartFragParentModel> ListTerbaru;
ArrayList<ArrayList<CartFragChildModel>> ListChildTerbaru;

public CartFragExpandable (Context context, ArrayList<CartFragParentModel>ListTerbaru, ArrayList<ArrayList<CartFragChildModel>> ListChildTerbaru){
    this.context=context;
    this.ListTerbaru=ListTerbaru;
    this.ListChildTerbaru=ListChildTerbaru;

}
@Override
public boolean areAllItemsEnabled()
{
    return true;
}


@Override
public CartFragChildModel getChild(int groupPosition, int childPosition) {
    return ListChildTerbaru.get(groupPosition).get(childPosition);
}

@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 CartFragChildModel childTerbaru = getChild(groupPosition, childPosition);

    CartFragExpandable.ViewHolder holder= null;
    notifyDataSetChanged();

    if (convertView == null) {
        LayoutInflater infalInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        convertView = infalInflater.inflate(R.layout.row_item_cart_child, null);

        holder=new CartFragExpandable.ViewHolder();
        holder.item_detail_tv = (TextView)convertView.findViewById(R.id.item_detail_tv);

        convertView.setTag(holder);
    }
    else{
        holder=(CartFragExpandable.ViewHolder)convertView.getTag();
    }

    String quantity = childTerbaru.getQuantity();
    String name = childTerbaru.getName();
    String price = childTerbaru.getPrice();
    String symbol = childTerbaru.getSymbol();
    holder.item_detail_tv.setText(quantity+"x "+name+" + "+symbol+price);

    return convertView;
}
@Override
public int getChildrenCount(int groupPosition) {
    return ListChildTerbaru.get(groupPosition).size();

}

@Override
public CartFragParentModel getGroup(int groupPosition) {
    return ListTerbaru.get(groupPosition);
}

@Override
public int getGroupCount() {
    return ListTerbaru.size();
}

@Override
public long getGroupId(int groupPosition) {
    return groupPosition;
}

@Override
public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {


    CartFragParentModel terbaruModel = (CartFragParentModel) getGroup(groupPosition);
    CartFragExpandable.ViewHolder holder= null;
    if (convertView == null) {
        LayoutInflater infalInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        convertView = infalInflater.inflate(R.layout.row_item_cart_parent, null);

     /*   ExpandableListView mExpandableListView = (ExpandableListView) parent;
        mExpandableListView.expandGroup(groupPosition);*/

        holder=new CartFragExpandable.ViewHolder();
        holder.name_tv=(TextView)convertView.findViewById(R.id.name_tv);
        holder.price_tv = (TextView)convertView.findViewById(R.id.price_tv);

        convertView.setTag(holder);

    }

    else{
        holder=(CartFragExpandable.ViewHolder)convertView.getTag();
    }
    String quantity = terbaruModel.getItem_quantity();
    String name = terbaruModel.getItem_name();
    String price = terbaruModel.getItem_price();
    String symbol = terbaruModel.getItem_symbol();

    holder.name_tv.setText(name+" x"+quantity);
    holder.price_tv.setText(symbol+price);

    return convertView;
}

@Override
public boolean hasStableIds() {
    return true;
}

@Override
public boolean isChildSelectable(int arg0, int arg1) {
    return true;
}

static class ViewHolder{
    TextView name_tv,price_tv,item_detail_tv;
}

}

请给我建议解决方案，非常感谢。

Answer 1

这会有所帮助。

对于空 child 更新 child 空列表不为空。将此行添加到 Activity class:

 if (!allJsonObject.has("extraItem")) { 
       cartProgress.setVisibility(View.GONE); 
       ListChild.add(listChildData); 
  }

然后returnchild数

@Override
public int getChildrenCount(int groupPosition) {
         return ListChildTerbaru.get(groupPosition).size();
       }

在 return child 计数时试试这个。

如果组的孩子计数为零，则 ExpandableListview 会出现 IndexOutOfBoundsException

ExpandableListview getting IndexOutOfBoundsException if group's childeren counts are Zero

android

listview

expandablelistview

indexoutofboundsexception