Android Studio ListView text name changes when scrolled

Question

When I scroll the listView down the text changes name.

List<ParseObject> ob;
listview = (ListView) rootView.findViewById(R.id.listview);
// Pass the results into an ArrayAdapter

ArrayList<Community> buses1 = new ArrayList<Community>();
//adapter = new ArrayAdapter<String>(getActivity(),
//R.layout.listview_item);

// Retrieve object "name" from Parse.com database
for (ParseObject country : ob) {
    Community busLinea1 = new Community();
    busLinea1.setArticolo((String) country.get("name"));
    busLinea1.setNome((String) country.get("Username"));
    busLinea1.setData((String) country.get("dataPubblicazione"));
    buses1.add(busLinea1);
    //adapter.add((String) country.get("name"));

    listview.setAdapter(new CommunityAdapter(getActivity(), buses1));
}

CommunityAdapter

public class CommunityAdapter extends BaseAdapter {

private Activity context_1;

private ArrayList<Community> post;

public CommunityAdapter(Activity context,
                         ArrayList<Community> post) {
    context_1 = context;
    this.post = post;
}


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


public Object getItem(int position) {
    return null;
}

public long getItemId(int position) {
    return 0;
}

public View getView(int position, View convertView, ViewGroup parent) {
    ViewHolder viewHolder1 = null;
    ViewHolder viewHolder2 = null;
    ViewHolder viewHolder3 = null;

    if (convertView == null) {
        convertView = LayoutInflater.from(context_1).inflate(
                R.layout.custom_row_community, null);
        viewHolder1 = new ViewHolder();
        viewHolder2 = new ViewHolder();
        viewHolder3 = new ViewHolder();


        viewHolder1.txt = (TextView) convertView
                .findViewById(R.id.t1);
        viewHolder2.txt = (TextView) convertView
                .findViewById(R.id.t2);
        viewHolder3.txt = (TextView) convertView
                .findViewById(R.id.t3);

        /**
         * At very first time when the List View row Item control's
         * instance is created it will be store in the convertView as a
         * ViewHolder Class object for the reusability purpose
         **/
        convertView.setTag(viewHolder1);
        convertView.setTag(viewHolder2);
        convertView.setTag(viewHolder3);


    } else {
        /**
         * Once the instance of the row item's control it will use from
         * already created controls which are stored in convertView as a
         * ViewHolder Instance
         * */
        viewHolder1 = (ViewHolder) convertView.getTag();
        viewHolder2 = (ViewHolder) convertView.getTag();
        viewHolder3 = (ViewHolder) convertView.getTag();
    }

    viewHolder1.txt.setText(post.get(position).articolo);
    viewHolder2.txt.setText(post.get(position).nome);
    viewHolder3.txt.setText(post.get(position).data);

    return convertView;
}

public class ViewHolder {
    public TextView txt;

}
}

This may help http://stackoverflow.com/questions/11945563/how-listviews-recycling-mechanism-works/14108676#14108676 — Muhammad Babar, May 18 '15 at 11:48
you need to do some thing in your 'CommunityAdapter', Post that too — Sree, May 18 '15 at 11:49
May be listview.setAdapter(new CommunityAdapter(getActivity(), buses1)); comes outside the for loop. — kalpana c, May 18 '15 at 11:50
you put it in answer, you can edit your question and add it :) unless that's your answer! will check it! — Mithun, May 18 '15 at 11:56

score 0 · Accepted Answer · answered May 18 '15 at 12:03

You've got the ViewHolder concept a little bit wrong here.

You should only use one ViewHolder for every item in the list and your ViewHolder should contain one field for every child view that you may want to update in the future.

Like this:

public class ViewHolder {
  public TextView txt1;
  public TextView txt2;
  public TextView txt3;
}

So your getView should look more like this:

public View getView(int position, View convertView, ViewGroup parent) {
    ViewHolder viewHolder = null;

    if (convertView == null) {
        convertView = LayoutInflater.from(context_1).inflate(
                R.layout.custom_row_community, null);
        viewHolder = new ViewHolder();

        viewHolder.txt1 = (TextView) convertView
                .findViewById(R.id.t1);
        viewHolder.txt2 = (TextView) convertView
                .findViewById(R.id.t2);
        viewHolder.txt3 = (TextView) convertView
                .findViewById(R.id.t3);


        /**
         * At very first time when the List View row Item control's
         * instance is created it will be store in the convertView as a
         * ViewHolder Class object for the reusability purpose
         **/
        convertView.setTag(viewHolder);

    } else {
        /**
         * Once the instance of the row item's control it will use from
         * already created controls which are stored in convertView as a
         * ViewHolder Instance
         * */
        viewHolder = (ViewHolder) convertView.getTag();
    }

    viewHolder.txt1.setText(post.get(position).articolo);
    viewHolder.txt2.setText(post.get(position).nome);
    viewHolder.txt3.setText(post.get(position).data);




    return convertView; }

You can read more about this pattern which often used in android here: http://developer.android.com/training/improving-layouts/smooth-scrolling.html

Good luck!

Android Studio ListView text name changes when scrolled

1 Answers1