如何确定哈希映射中键的第一个和最后一个子项?

时间:2016-06-26 06:37:20

标签: java android hashmap expandablelistview

我有一个expandableList视图。它的子元素是从哈希映射填充的。我想要做的是我想从Hash地图中显示一个键的第一个和最后一个孩子的视图,然后为其他人隐藏。目前我试图通过以下方式实现这一目标,但它无法正常工作。下面提到的是我的EpandableListAdapter类的getChildView方法。

@Override
    public View getChildView(int groupPosition, final int childPosition,
                             boolean isLastChild, View convertView, ViewGroup parent) {

        final String childText = (String) getChild(groupPosition, childPosition);


        LinearLayout titleLayout = null;
        LinearLayout sumTotalLayout = null;
        if (convertView == null) {
            LayoutInflater infalInflater = (LayoutInflater) this._context
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = infalInflater.inflate(R.layout.order_form_history_viewable, null);
            titleLayout = (LinearLayout) convertView.findViewById(R.id.llOrderHistroryTitles);
            sumTotalLayout = (LinearLayout) convertView.findViewById(R.id.llOrderHistroryTotals);
        }


        if (childPosition==0 && titleLayout != null) {
            titleLayout.setVisibility(View.VISIBLE);
        } else if (titleLayout != null) {

            titleLayout.setVisibility(View.GONE);
        }

      //  int childSize = this._listDataChild.get(this._listDataHeader.get(groupPosition))
                .size();
        if (isLastChild && sumTotalLayout != null) {
            sumTotalLayout.setVisibility(View.VISIBLE);
        } else if (sumTotalLayout != null) {
            sumTotalLayout.setVisibility(View.GONE);
        }
//        if (childPosition == childSize-1 && sumTotalLayout!=null){
//            sumTotalLayout.setVisibility(View.VISIBLE);
//        }else if (sumTotalLayout!=null){
//            sumTotalLayout.setVisibility(View.GONE);
//        }


        TextView txtListChild = (TextView) convertView
                .findViewById(R.id.tvOrderlistBrand);

        txtListChild.setText(childText);
        return convertView;
    }

1 个答案:

答案 0 :(得分:0)

您正在检查if (convertView == null),但没有其他部分,即 covertView 不等于null。试着说,它会起作用。