notifydataSetChanged working but only showing 1 result in listview Android

Question

Hi i have an issue where only 1 result is being shown when i call a notifydataSetChanged function. I have read in this forum that the Array list needs to be cleared, then the data needs to be added for the notifydataSetChanged to work properly. I have followed that, but the problem is when the new data arrives it clears all the other data and only shows the latest item from the list. I know its a clear() issue, but i cant work out how to fix it. Any suggestions would be gratefully appreciated.

My Adapter :

public MessageAdapter(Activity context, ArrayList<ArrayList<ReadMessage>> list) {
    mContext = context;
    mList = list;
    mLayoutInflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}

@Override
public int getCount() {
    return mList.size();
}

@Override
public Object getItem(int pos) {
    return mList.get(pos);
}

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


@Override
public View getView(int position, View convertView, ViewGroup parent) {
    View v = convertView;
    CompleteListViewHolder viewHolder;
    if (convertView == null) {
        LayoutInflater li = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        v = li.inflate(R.layout.list_row, null);
        viewHolder = new CompleteListViewHolder(v);
        v.setTag(viewHolder);
    } else {
        viewHolder = (CompleteListViewHolder) v.getTag();
    }
    viewHolder.messageText.setText(mList.get(position).get(position).getMessage());
    viewHolder.fromText.setText(mList.get(position).get(position).getSender());
    return v;
}

}

class CompleteListViewHolder {
    public TextView messageText;
    public TextView fromText;

public CompleteListViewHolder(View base) {
    messageText = (TextView) base.findViewById(R.id.message);
    fromText = (TextView) base.findViewById(R.id.user);
}

The following method is where i am adding items to the list :

  private void addItemsToList() {
       sentMessages.clear();
         sentMessages.add(localstoragehandler.getUserComments(MessageService.USERNAME, friendUsername()));
      messageAdapter.notifyDataSetChanged();
}

The addItemsToList() is called when new data arrives from the web service.

Thanks

because it is not the same references .... adapter using (simple version) copy of it — Selvin, Jun 09 '15 at 13:39
Your notifyDataSetChanges is very strange, you need just to change data in the list if it needs to and call it, no refreshAdapter is needed — Nik Myers, Jun 09 '15 at 13:39
I only added refreshAdapter as i read on a post earlier that it may fix it — n4zg, Jun 09 '15 at 13:42
I have updated the code removing the refreshAdapter function. — n4zg, Jun 09 '15 at 13:46

score 0 · Answer 1 · answered Jun 09 '15 at 13:47

0

What's probably happening is that your list sentMessages is what you used to initialize your MessageAdapter, correct? By calling mList.clear() since it points to the same object as sentMessages, you are clearing everything from both lists (which is really just the exact same list). What I would do is change your MessageAdapter constructor to the following:

public MessageAdapter(Activity context, ArrayList<ArrayList<ReadMessage>> list) {
    mContext = context;
    mList = new ArrayList<ArrayList<ReadMessage>>();
    mList.addAll(list);
    mLayoutInflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}

answered Jun 09 '15 at 13:47

Joseph Roque

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Thank for the answer, i changed the consructor, but now im not getting no items in the array list. any sugestions please. – n4zg Jun 09 '15 at 13:51
@n4zg Yeah, I took a second look and realized that might happen. Can I ask why you need to clear the ArrayList? I know you said you've read it on this forum, but I'm really not sure you need to. What happens if you keep your original code, but get rid of the `clear()` call and the `addAll()` call? So you just call `sentMessages.add(...)` and then `notifyDataSetChanged()`? – Joseph Roque Jun 09 '15 at 13:57
il give it a go now , previously i have tried something similar with my constructor and it didnt update the arraylist, il try with the your constructor now – n4zg Jun 09 '15 at 13:59
removing clear() with new constructor, didnt work, so i reverted to my constructor, i get all the results in the listview but when new data arrives the listview is not updated until i refresh the whole fragement – n4zg Jun 09 '15 at 14:05

notifydataSetChanged working but only showing 1 result in listview Android

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