EditText loses content on scroll in ListView

Question

I have list item with EditText in it, I dont know how many items there will be. I have a problem when I enter some text in EditText, and then scroll down a ListView, after I've scroll up again there is no text in my first EditText, or there is some text from other EditText from ListView.

I've tried TextWatcher, and saving data to array, but problems is that returned position of view in ListView isnt always right, so I lost some data from array. -.-

How to detect correct position of view in ListView?

For example:

If I have 10 items in ListView, and only 5 of them are currently visible. Adapter return position from 0 to 4...thats ok. When I scroll down position of item 6 is 0...wtf? and i lose data from array on position 0 :)

Im using ArrayAdapter.

Please help.

Here's some code:

public View getView(int position, View convertView, ViewGroup parent) {

    tmp_position = position;

    if (convertView == null) {

        holder = new ViewHolder();

        LayoutInflater vi = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        convertView = vi.inflate(R.layout.element_in_game, null);

        holder.scoreToUpdate = (EditText) convertView
                .findViewById(R.id.elementUpdateScore);

        holder.scoreToUpdate.addTextChangedListener(new TextWatcher() {

            @Override
            public void onTextChanged(CharSequence s, int start,
                    int before, int count) {
                scoresToUpdate[tmp_position] = s.toString();
            }

            @Override
            public void beforeTextChanged(CharSequence s, int start,
                    int count, int after) {

            }

            @Override
            public void afterTextChanged(Editable s) {

            }
        });

        initScoresToUpdateEditTexts(holder.scoreToUpdate, hint);

        convertView.setTag(holder);

    } else {

        holder = (ViewHolder) convertView.getTag();

        holder.scoreToUpdate.setText(scoresToUpdate[tmp_position]);

    }

    return convertView;
}

Answer 1

I had a related issue that I solved. Each row of my ListView has a different View (it contains different controls. EditView, ImageView, TextView). I want the data entered or selected in the those controls to persist even when the control is scrolled off the screen. The solution I used was to implement the following methods in ArrayAdapter like this:

public int getViewTypeCount() {
    return getCount();
}

public int getItemViewType(int position) {
    return position;
}

This will make sure that when getView() gets called it passes the same View instance that was returned from getView() on the first call.

public View getView(int position, View convertView, ViewGroup parent) {

  if (convertView != null)
    return convertView;
  else
  // create new view
}

Answer 2

I just recently was looking for a similar solution and found that using the textChangeListener NOT to the best approach. I answered a related question here:

https://stackoverflow.com/a/13312282/1812518

It is my first post, but I hope it is helpful enough.

Answer 3

If you will only have ~10 rows, don't bother with the ListView. Just put them in a vertical LinearLayout and wrap that in a ScrollView, and it will save you some headache.

If you are going to have dozens or hundreds of rows, I suggest that you come up with a better UX paradigm than EditText widgets in ListView rows.

All that being said, it feels like you are not handling your row recycling properly, or are unaware that rows get recycled. If you have 10 items in your ListAdapter, and you only have room to display 5 rows with EditText widgets, you should not wind up with 10 EditText widgets when the user scrolls to the bottom. You should wind up with 5-7 -- the ones on the screen, and perhaps another one or two for recycling when the user scrolls next.

This free excerpt from one of my books goes through the process of creating custom subclasses of ArrayAdapter and getting the recycling working. It also covers having an interactive row, using a RatingBar for user input. That is far easier than an EditText, because all you have to worry about are click events. You are welcome to try to expand upon that technique with EditText widgets and TextWatcher listeners, but I'm not a fan.

Answer 4

A better way is Creating EditText at run time and setting its id as the position argument

of getView() method. so now when text is added, store it in a Vector variable (class

variable), and in the getView method based on position variable set the Text (Which you can

get using elementAt() method of vector) of corresponding EditText.

and don't forget to add this EditText to the inflated View.