Searching a custom listview

Question

I was curious on how to make a listview with a custom adapter searchable. I followed a tutorial and got everything set up, but the app crashes when I try to type anything in the EditText. Now I know why the app crashes, I just don't know how to fix it.

Here is the code to my MainActivity:

@Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        Context ctx = getApplication();
        Resources res = ctx.getResources();

        String[] options = res.getStringArray(R.array.item_ids);
        String[] ids = res.getStringArray(R.array.item_names);
        TypedArray icons = res.obtainTypedArray(R.array.item_images);

        setListAdapter(new ItemIDAdapter(ctx, R.layout.idslistitem, ids, options, icons));
    }

        @Override
        public boolean onCreateOptionsMenu(Menu menu) {
            // Get the options menu view from menu.xml in menu folder
            getSupportMenuInflater().inflate(R.menu.items_menu, menu);

            // Locate the EditText in menu.xml
            editsearch = (EditText) menu.findItem(R.id.menu_search).getActionView();

            // Capture Text in EditText
            editsearch.addTextChangedListener(textWatcher);

            // Show the search menu item in menu.xml
            MenuItem menuSearch = menu.findItem(R.id.menu_search);

            menuSearch.setOnActionExpandListener(new OnActionExpandListener() {

                // Menu Action Collapse
                @Override
                public boolean onMenuItemActionCollapse(MenuItem item) {
                    // Empty EditText to remove text filtering
                    editsearch.setText("");
                    editsearch.clearFocus();
                    return true;
                }

                // Menu Action Expand
                @Override
                public boolean onMenuItemActionExpand(MenuItem item) {
                    // Focus on EditText
                    editsearch.requestFocus();

                    // Force the keyboard to show on EditText focus
                    InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
                    imm.toggleSoftInput(InputMethodManager.SHOW_FORCED, 0);
                    return true;
                }
            });

            // Show the settings menu item in menu.xml
            MenuItem menuSettings = menu.findItem(R.id.home);

            // Capture menu item clicks
            menuSettings.setOnMenuItemClickListener(new OnMenuItemClickListener() {

                @Override
                public boolean onMenuItemClick(MenuItem item) {
                    Intent intent2 = new Intent(ItemId.this, Home.class);
                    startActivity(intent2);
                    return true;
                }

            });

            return true;
        }

        // EditText TextWatcher
        private TextWatcher textWatcher = new TextWatcher() {

            @Override
            public void afterTextChanged(Editable s) {
                // TODO Auto-generated method stub
                String text = editsearch.getText().toString()
                        .toLowerCase(Locale.getDefault());
                adapter.getFilter().filter(text);
            }

            @Override
            public void beforeTextChanged(CharSequence arg0, int arg1, int arg2,
                    int arg3) {
                // TODO Auto-generated method stub

            }

            @Override
            public void onTextChanged(CharSequence arg0, int arg1, int arg2,
                    int arg3) {
                // TODO Auto-generated method stub

            }

        };

And here is the code to my custom listview adapter:

public class ItemIDAdapter extends ArrayAdapter<String> {

    public LayoutInflater mInflater;

    public String[] mStrings;
    public String[] mIds;
    public TypedArray mIcons;   
    public int mViewResourceId;
    ArrayAdapter<String> adapter;

    public ItemIDAdapter(Context ctx, int viewResourceId,
            String[] strings, String[] ids, TypedArray icons) {
        super(ctx, viewResourceId, strings);

        mInflater = (LayoutInflater)ctx.getSystemService(
                Context.LAYOUT_INFLATER_SERVICE);

        mStrings = strings;
        mIds = ids;
        mIcons = icons;       
        mViewResourceId = viewResourceId;
    }

    @Override
    public int getCount() {
        return mStrings.length;
    }

    @Override
    public String getItem(int position) {
        return mStrings[position];
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        convertView = mInflater.inflate(mViewResourceId, null);

        ImageView iv = (ImageView)convertView.findViewById(R.id.option_icon);
        iv.setImageDrawable(mIcons.getDrawable(position));

        TextView tv = (TextView)convertView.findViewById(R.id.option_text);
        tv.setText(mStrings[position]);

        TextView tv1 = (TextView)convertView.findViewById(R.id.itemids);
        tv1.setText(mIds[position]);

        return convertView;
    }

}

The reason the app crashes when I try to search, is because in the TextWatcher, this line: adapter.getFilter().filter(text); adapter is only defined at the top of my main activity, but it isn't used with my listview at ALL. I'm stuck here and really don't know what to replace adapter with, because ItemIDAdapter doesn't work. Thanks for your help!

Answer 1

Replace

setListAdapter(new ItemIDAdapter(ctx, R.layout.idslistitem, ids, options, icons));

with

adapter = new ItemIDAdapter(ctx, R.layout.idslistitem, ids, options, icons)

setListAdapter(adapter );