java - 如何使用 HashMap 在 ExpandableListView 中实现过滤器

Question

所以，我看到了一个例子，如果我为可扩展 ListView 初始化两个数组，但在我的例子中，我有一个用于头数据的数组，一个用于子数据的字符串，并且两者都存储在 HashMap 中。以 here 为例。我怎样才能实现这个目标？

更新

我已经向适配器添加了一个新的过滤器，但由于某种原因我没有收到任何数据，甚至没有收到错误。我做错了什么？

public class SearchExpadanbleAdapter extends BaseExpandableListAdapter
                    implements Filterable {
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 SearchExpadanbleAdapter(Context context, List<String> listDataHeader,
                             HashMap<String, List<String>> listChildData) {
    this._context = context;
    this._listDataHeader = listDataHeader;
    this._listDataChild = listChildData;
}

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

@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 Object getChild(int groupPosition, int childPosititon) {
    return this._listDataChild.get(this._listDataHeader.get(groupPosition))
            .get(childPosititon);
}

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

@Override
public long getChildId(int groupPosition, int childPosition) {
    return childPosition;
}

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

@Override
public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup viewGroup) {
    String headerTitle = (String) getGroup(groupPosition);
    if (convertView == null) {
        LayoutInflater infalInflater = (LayoutInflater) this._context
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        convertView = infalInflater.inflate(R.layout.suggest_item_header, null);
    }

    TextView lblListHeader = (TextView) convertView
            .findViewById(R.id.text_header);
    lblListHeader.setText(headerTitle);

    return convertView;
}

@Override
public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup viewGroup) {
    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.suggest_item, null);
    }

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

    txtListChild.setText(childText);
    return convertView;
}

@Override
public boolean isChildSelectable(int i, int i1) {
    return true;
}

public void notifyDataSetInvalidated() {
    super.notifyDataSetInvalidated();
}

@Override
public Filter getFilter() {
    Filter filter = new Filter() {
        @Override
        protected FilterResults performFiltering(CharSequence constraint) {
            FilterResults filterResults = new FilterResults();
            if (!TextUtils.isEmpty(constraint)) {

                // Retrieve the autocomplete results.
                Map<String, List<String>> searchData = new HashMap<>();

                for (Map.Entry<String, List<String>> map : _listDataChild.entrySet()) {
                    if (map.getKey().toLowerCase().startsWith(constraint.toString().toLowerCase())) {
                        _listDataHeader.add(map.getKey());
                        searchData.put(map.getKey(), map.getValue());
                    }
                }

                // Assign the data to the FilterResults
                filterResults.values = searchData;
                filterResults.count = searchData.size();
            }
            return filterResults;
        }

        @Override
        protected void publishResults(CharSequence constraint, FilterResults results) {
            if (results.values != null) {
                _listDataChild = (HashMap<String, List<String>>) results.values;
                notifyDataSetChanged();
            }
        }
    };
    return filter;
}

Answer 1

首先，您创建一个副本列表并在副本列表中进行搜索，然后在发布结果后定义主列表。

public class SearchExpadanbleAdapter extends BaseExpandableListAdapter
    implements Filterable {
private Context _context;
private List<String> _listDataHeader; // header titles
// child data in format of header title, child title
private HashMap<String, List<String>> _listDataChild;
private HashMap<String, List<String>> _listDataChildCopy;

public SearchExpadanbleAdapter(Context context, List<String> listDataHeader,
                               HashMap<String, List<String>> listChildData) {
    this._context = context;
    this._listDataHeader = listDataHeader;
    this._listDataChild = listChildData;
    _listDataChildCopy.addAll(_listChildData);
}

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

@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 Object getChild(int groupPosition, int childPosititon) {
    return this._listDataChild.get(this._listDataHeader.get(groupPosition))
            .get(childPosititon);
}

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

@Override
public long getChildId(int groupPosition, int childPosition) {
    return childPosition;
}

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

@Override
public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup viewGroup) {
    String headerTitle = (String) getGroup(groupPosition);
    if (convertView == null) {
        LayoutInflater infalInflater = (LayoutInflater) this._context
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        convertView = infalInflater.inflate(R.layout.suggest_item_header, null);
    }

    TextView lblListHeader = (TextView) convertView
            .findViewById(R.id.text_header);
    lblListHeader.setText(headerTitle);

    return convertView;
}

@Override
public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup viewGroup) {
    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.suggest_item, null);
    }

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

    txtListChild.setText(childText);
    return convertView;
}

@Override
public boolean isChildSelectable(int i, int i1) {
    return true;
}

public void notifyDataSetInvalidated() {
    super.notifyDataSetInvalidated();
}

@Override
public Filter getFilter() {
    if (mFilter == null) {
        mFilter = new ItemFilter();
    }
    return mFilter;
}

private class ItemFilter extends Filter {

    protected FilterResults performFiltering(CharSequence constraint) {

        FilterResults results = new FilterResults();
        if (constraint != null && constraint.length() > 0) {
            HashMap<String, List<String>> filterList = new HashMap<>();

            for (int i = 0; i < _listDataChildCopy.size(); i++) {
                if ((_listDataChildCopy.get(i).getName().toUpperCase())
                        .contains(constraint.toString().toUpperCase())) {
                    ObjectName name = _listDataChildCopy.get(i);
                    filterList.add(peopleName);
                }
            }
            results.count = filterList.size();
            results.values = filterList;

        } else {
            results.count = _listDataChildCopy.size();
            results.values = _listDataChildCopy;
        }
        return results;
    }

    @Override
    protected void publishResults(CharSequence constraint, FilterResults results) {

        _listDataChild = (HashMap<String, List<String>>) results.values;

        notifyDataSetChanged();
    }
}