ListView in ArrayAdapter order get's mixed up when scrolling

Question

Hi, I have a ListView in a custom ArrayAdapter that displays an icon ImageView and a TextView in each row. When I make the list long enough to let you scroll through it, the order starts out right, but when I start to scroll down, some of the earlier entries start re-appearing. If I scroll back up, the old order changes. Doing this repeatedly eventually causes the entire list order to be seemingly random. So scrolling the list is either causing the child order to change, or the drawing is not refreshing correctly.

What could cause something like this to happen? I need the order the items are displayed to the user to be the same order they are added to the ArrayList, or at LEAST to remain in one static order. If I need to provide more detailed information, please let me know. Any help is appreciated. Thanks.

Answer 1

The ListView reuses view objects when you scroll. Are you overriding the getView method? You need to make sure you set each property for every view, don't assume that it will remember what you had before. If you post that method, someone can probably point you at the part that is incorrect.

Answer 2

Interesting, I didn't know that. Yes I override getView in the custom ArrayAdapter, and your suggestion indeed fixed it. I only set the icon and text if the view was being created, not if the view was already created and just being updated. By telling it to set the icon and text of a new OR existing view, it fixed the problem real easy. Thank you very much, you saved me a world of pain and time.

Answer 3

'm have same issue. i have list of items {checkbox,textview} as list item. i have extended ArrayAdapter in one class. and override public View getView(int position, View convertView, ViewGroup parent)

initial only for 7 items getView is called. when i scroll down then again getView is called ..

if i click checkbox of item #1 it automatically gets Checked for item in list that is not currently visible in scroll bar.

i don't know y it happens. help pls.

Answer 4

I was having similar issues, but when clicking an item in the custom list, the items on the screen would reverse in sequence. If I clicked again, they'd reverse back to where they were originally.

After reading this, I checked my code where I overload the getView method. I was getting the view from the convertedView, and if it was null, that's when I'd build my stuff. However, after placing a breakpoint, I found that it was calling this method on every click and on subsequent clicks, the convertedView was not null therefore the items weren't being set.

Here is an example of what it was:

public View getView(int position, View convertView, ViewGroup parent)
{
    View view = convertView;
    if (view == null)
    {
        LayoutInflater vi = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        view = vi.inflate(R.layout.listitemrow, null);

        RssItem rssItem = (RssItem) super.getItem(position);
        if (rssItem != null)
        {
            TextView title = (TextView) view.findViewById(R.id.rowtitle);
            if (title != null)
            {
                title.setText(rssItem.getTitle());
            }
        }
    }
    return view;
}

The subtle change is moving the close brace for the null check on the view to just after inflating:

public View getView(int position, View convertView, ViewGroup parent)
{
    View view = convertView;
    if (view == null)
    {
        LayoutInflater vi = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        view = vi.inflate(R.layout.listitemrow, null);
    }
    RssItem rssItem = (RssItem) super.getItem(position);
    if (rssItem != null)
    {
        TextView title = (TextView) view.findViewById(R.id.rowtitle);
        if (title != null)
        {
            title.setText(rssItem.getTitle());
        }
    }
    return view;
}

I hope this helps others who experience this same problem.