AutoCompleteTextView 自定义过滤结果被忽略

Question

我为 AutoCompleteTextView 创建了一个自定义适配器。

package ...

import ...

public class CardSuggestionAdapter extends ArrayAdapter<String> implements Filterable {

    private final LayoutInflater mInflater;
    private Activity context;
    private int mFieldId, mResource;

    CardSuggestionAdapter(Activity context, String[] names) {
        super(context, R.layout.card_suggestion, R.id.name_label, names);
        this.context = context;
        this.mFieldId = R.id.name_label;
        this.mResource = R.layout.card_suggestion;
        this.mInflater = LayoutInflater.from(context);
    }

    @NonNull
    @Override
    public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
        return createViewFromResource(mInflater, position, convertView, parent, mResource);
    }

    @NonNull
    @Override
    public Filter getFilter() {
        return new CardsFilter();
    }

    private View createViewFromResource(@NonNull LayoutInflater inflater, int position, @Nullable
            View convertView, @NonNull ViewGroup parent, int resource) {
        View view = convertView;
        final TextView text;

        ViewHolder viewHolder;
        if (convertView == null) {
            view = inflater.inflate(resource, parent, false);
            viewHolder = new ViewHolder(view);
            view.setTag(viewHolder);
        } else {
            viewHolder = (ViewHolder) view.getTag();
        }
        text = view.findViewById(mFieldId);
        if (text == null) {
            throw new RuntimeException("Failed to find view with ID "
                    + context.getResources().getResourceName(mFieldId)
                    + " in item layout");
        }

        final String item = getItem(position);
        viewHolder.name.setText(item);
        viewHolder.name.setTypeface(Typeface.createFromAsset(
                MarsPDA.assetManager, "fonts/prototype.ttf"));

        return view;
    }

    class ViewHolder {

        TextView name;

        ViewHolder(View v) {
            name = v.findViewById(R.id.name_label);
        }
    }

    private class CardsFilter extends Filter {

        @Override
        protected FilterResults performFiltering(CharSequence constraint) {
            if (constraint != null) {
                final List<String> suggestions = new ArrayList<>();
                final FilterResults fs = new FilterResults();
                return fs;
            } else {
                return new FilterResults();
            }
        }

        @Override
        protected void publishResults(CharSequence constraint, FilterResults results) {
            if (results != null && results.count > 0) {
                notifyDataSetChanged();
            } else {
                notifyDataSetInvalidated();
            }
        }
    }
}

performFiltering 的这种实现显然不会显示任何建议。

我尝试从原始ArrayAdapter 类中复制performFiltering 方法，并查看此论坛上发现的Filter 的其他一些实现， 但即使我实际上将任何内容添加到suggestions 列表并设置fs.values = suggestions; 和fs.count = suggestions.size();，适配器也会显示传递给构造函数的names 数组的所有成员。 为什么会这样？

Answer 1

我认为问题出在管理列表中，您可以尝试以下更改 声明list original和filter，然后在构造函数中初始化。

覆盖获取计数方法。

@Override
    public int getCount() {
        return names.size();
    }

在过滤器类中进行如下更改：

private class CardsFilter extends Filter {

        @Override
        protected FilterResults performFiltering(CharSequence constraint) {

            FilterResults results = new FilterResults();        // Holds the results of a filtering operation in values
            List<String> FilteredArrList = new ArrayList<String>();
            if (constraint == null || constraint.length() == 0) {

                // set the Original result to return
                results.count = namesOriginal.size();
                results.values = namesOriginal;
            } else {
                constraint = constraint.toString().toLowerCase();
                for (int i = 0; i < namesOriginal.size(); i++) {
                    String data = namesOriginal.get(i);
                    if (data.toLowerCase().startsWith(constraint.toString())) {
                        FilteredArrList.add(data);
                    }
                }
                // set the Filtered result to return
                results.count = FilteredArrList.size();
                results.values = FilteredArrList;
            }
            return results;

        }

        @Override
        protected void publishResults(CharSequence constraint, FilterResults results) {
            if (results != null && results.count > 0) {
                names= (ArrayList<String>) results.values;
                notifyDataSetChanged();
            } else {
                names.addAll(namesOriginal);
                notifyDataSetInvalidated();
            }
        }
    }

希望这会有所帮助。