ListView中的自定义过滤ArrayAdapter

Question

我是Android的初学者,但我尝试进行自定义列表视图过滤,我以某种方式工作.我唯一的问题是我保留所有值("原始"ArrayList)的ArrayList在每个过滤中的项目上越来越低.我无法解释这一点,但我认为你可以以某种方式帮助我.

无论如何这里是Custom ArrayAdaptor:

public class PkmnAdapter extends ArrayAdapter<Pkmn> {

private ArrayList<Pkmn> original;
private ArrayList<Pkmn> fitems;
private Filter filter;

public PkmnAdapter(Context context, int textViewResourceId, ArrayList<Pkmn> items) {
        super(context, textViewResourceId, items);
        this.original = items;//new ArrayList<Pkmn>();
        this.fitems = items;//new ArrayList<Pkmn>();
}

@Override
public void add(Pkmn item){
    original.add(item);
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
        View v = convertView;
        if (v == null) {
            LayoutInflater vi = (LayoutInflater)getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            v = vi.inflate(R.layout.row, null);
        }
        Pkmn pkmn = original.get(position);
        if (pkmn != null) {
                TextView tt = (TextView) v.findViewById(R.id.RlabPName);
                TextView dex = (TextView)v.findViewById(R.id.RlabDex);
                ImageView img = (ImageView)v.findViewById(R.id.RimgPkmn);

                if (tt != null) { tt.setText(pkmn.getName()); }
                if (dex != null){ dex.setText(CalcDex(pkmn.getId())); }
                if (img != null){
                    int resId = getContext().getResources().getIdentifier("dex" + pkmn.getId(), "drawable", "com.compileguy.pokebwteam");
                    img.setImageResource(resId);
                }
        }
        return v;
}

@Override
public Filter getFilter()
{
    if (filter == null)
        filter = new PkmnNameFilter();

    return filter;
}

private class PkmnNameFilter extends Filter
{
        @Override
        protected FilterResults performFiltering(CharSequence constraint)
        {   
            FilterResults results = new FilterResults();
            String prefix = constraint.toString().toLowerCase();

            if (prefix == null || prefix.length() == 0)
            {
                ArrayList<Pkmn> list = new ArrayList<Pkmn>(original);
                results.values = list;
                results.count = list.size();
            }
            else
            {
                final ArrayList<Pkmn> list = original;

                int count = list.size();
                final ArrayList<Pkmn> nlist = new ArrayList<Pkmn>(count);

                for (int i=0; i<count; i++)
                {
                    final Pkmn pkmn = list.get(i);
                    final String value = pkmn.getName().toLowerCase();

                    if (value.startsWith(prefix))
                    {
                        nlist.add(pkmn);
                    }
                }
                results.values = nlist;
                results.count = nlist.size();
            }
            return results;
        }

        @SuppressWarnings("unchecked")
        @Override
        protected void publishResults(CharSequence constraint, FilterResults results) {
            fitems = (ArrayList<Pkmn>)results.values;
            clear();
            int count = fitems.size();
            for (int i=0; i<count; i++)
            {
                Pkmn pkmn = (Pkmn)fitems.get(i);
                add(pkmn);
            }

            if (fitems.size() > 0)
                notifyDataSetChanged();
            else
                notifyDataSetInvalidated();
        }

    }


private String CalcDex(int id){
    String s = String.valueOf(id);
    if (s.length() == 1)
        s = "00"+s;
    else if (s.length() == 2)
        s = "0"+s;
    return '#'+s;
}

}

注意:列表视图正确显示项目,但是当我为exaple删除编辑框中的一个字母(触发过滤)时,问题就出现了.

---编辑---

@Janusz:非常感谢你的回答.这解决了我的问题.

以下是适用于我的源代码,因此如果有人遇到同样的问题,他们可以试试这个:

private ArrayList<Pkmn> original;
private ArrayList<Pkmn> fitems;
private Filter filter;

public PkmnAdapter(Context context, int textViewResourceId, ArrayList<Pkmn> items) {
        super(context, textViewResourceId, items);
        this.original = new ArrayList<Pkmn>(items);
        this.fitems = new ArrayList<Pkmn>(items);
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
        View v = convertView;
        if (v == null) {
            LayoutInflater vi = (LayoutInflater)getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            v = vi.inflate(R.layout.row, null);
        }
        Pkmn pkmn = fitems.get(position);
        if (pkmn != null) {
                TextView tt = (TextView) v.findViewById(R.id.RlabPName);
                TextView dex = (TextView)v.findViewById(R.id.RlabDex);
                ImageView img = (ImageView)v.findViewById(R.id.RimgPkmn);

                if (tt != null) { tt.setText(pkmn.getName()); }
                if (dex != null){ dex.setText(CalcDex(pkmn.getId())); }
                if (img != null){
                    int resId = getContext().getResources().getIdentifier("dex" + pkmn.getId(), "drawable", "com.compileguy.pokebwteam");
                    img.setImageResource(resId);
                }
        }
        return v;
}

@Override
public Filter getFilter()
{
    if (filter == null)
        filter = new PkmnNameFilter();

    return filter;
}

private class PkmnNameFilter extends Filter
{
        @Override
        protected FilterResults performFiltering(CharSequence constraint)
        {   
            FilterResults results = new FilterResults();
            String prefix = constraint.toString().toLowerCase();

            if (prefix == null || prefix.length() == 0)
            {
                ArrayList<Pkmn> list = new ArrayList<Pkmn>(original);
                results.values = list;
                results.count = list.size();
            }
            else
            {
                final ArrayList<Pkmn> list = new ArrayList<Pkmn>(original);
                final ArrayList<Pkmn> nlist = new ArrayList<Pkmn>();
                int count = list.size();

                for (int i=0; i<count; i++)
                {
                    final Pkmn pkmn = list.get(i);
                    final String value = pkmn.getName().toLowerCase();

                    if (value.startsWith(prefix))
                    {
                        nlist.add(pkmn);
                    }
                }
                results.values = nlist;
                results.count = nlist.size();
            }
            return results;
        }

        @SuppressWarnings("unchecked")
        @Override
        protected void publishResults(CharSequence constraint, FilterResults results) {
            fitems = (ArrayList<Pkmn>)results.values;

            clear();
            int count = fitems.size();
            for (int i=0; i<count; i++)
            {
                Pkmn pkmn = (Pkmn)fitems.get(i);
                add(pkmn);
            }
        }

    }
}

Answer 1

你的问题是这样的:

this.original = items;
this.fitems = items;

Items是您用于ListView的列表,并将其放在两个不同的变量中,不会生成两个不同的列表.您只给列表项两个不同的名称.

您可以使用:

this.fitems = new ArrayList(items);

应生成一个新列表,此列表中的更改只会更改fitems列表.