Android ArrayAdapter array filtering issues

Question

How I wanted to use the Custom List adapter so that I could style the list, but the Filter function does not work. I got basic filtering, but the application crashes as soon as the list of filtered results is less than the number of lists displayed when filtering starts.

There is also a second problem that arises in my code that I'm not sure if it is connected, but when clear(); runs in publishResults, then the application also crashes.

Here is the code I'm using.

 package com.android.example; import java.util.ArrayList; import java.util.Arrays; import java.util.Collections; import java.util.List; import android.content.Context; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.ArrayAdapter; import android.widget.Filter; import android.widget.TextView; public class CustomListAdapter extends ArrayAdapter<String> { private Context mContext; private String[] items; private String[] filtered; public CustomListAdapter(Context context, int textViewResourceId, String[] items) { super(context, textViewResourceId, items); this.filtered = items; this.items = filtered; setNotifyOnChange(true); mContext = context; } @Override public View getView(int position, View convertView, ViewGroup parent) { View v = convertView; if (v == null) { LayoutInflater vi = (LayoutInflater)mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE); v = vi.inflate(R.layout.list_item, null); } String o = filtered[position]; if (o != null) { TextView tt = (TextView) v.findViewById(R.id.tvViewRow); if (tt != null) { tt.setText("Name: "+o); } } return v; } public void notifyDataSetInvalidated() { super.notifyDataSetInvalidated(); } private Filter filter; public Filter getFilter() { if(filter == null) filter = new NameFilter(); return filter; } private class NameFilter extends Filter { @Override protected FilterResults performFiltering(CharSequence constraint) { // NOTE: this function is *always* called from a background thread, and // not the UI thread. constraint = constraint.toString().toLowerCase(); FilterResults result = new FilterResults(); if(constraint != null && constraint.toString().length() > 0) { ArrayList<String> filt = new ArrayList<String>(); List<String> lItems = new ArrayList<String>(); synchronized (items) { lItems = Arrays.asList(items); //Collections.copy(lItems, Arrays.asList(items)); } for(int i = 0, l = lItems.size(); i < l; i++) { String m = lItems.get(i); if(m.toLowerCase().startsWith(constraint.toString())) filt.add(m); } result.count = filt.size(); result.values = filt.toArray(new String[0]); } else { synchronized(items) { result.values = items; result.count = Arrays.asList(items).size(); } } return result; } @Override protected void publishResults(CharSequence constraint, FilterResults results) { // NOTE: this function is *always* called from the UI thread. filtered = (String[])results.values; notifyDataSetChanged(); clear(); notifyDataSetInvalidated(); } } 

}

Answer 1

I have the same problem. Just put the getCount () method in your adapter class. It should return a filtered count. Something like that:

 public int getCount() { return mItems.size(); } 

I am filtering mItems.

Answer 2

Try changing the publishResults method as follows:

  @Override public void publishResults(CharSequence constraint, FilterResults results) { List<T> filtered = (ArrayList<T>) results.values; adapter.notifyDataSetChanged(); adapter.clear(); if (filtered != null) { for (int i = 0; i < filtered.size(); i++) adapter.add(filtered.get(i)); } adapter.notifyDataSetInvalidated(); } }