Android: how to refresh ListView contents?

Question

My ListView is using an extension of BaseAdapter, I can not get it to refresh properly. When I refresh, it appears that the old data draws on top of the new data, until a scroll event happens. The old rows draw on top of the new rows, but the old rows disappear when I start scrolling.

I have tried calling invalidateViews(), notifyDataSetChanged(), and notifyDataSetInvalidated(). My code looks something like:

private void updateData() {    List<DataItems> newList = getNewList();     MyAdapter adapter = new MyAdapter(getContext());    //my adapter holds an internal list of DataItems    adapter.setList(newList);    mList.setAdapter(adapter);    adapter.notifyDataSetChanged();    mList.invalidateViews(); } 

Answer 1

To those still having problems, I solved it this way:

List<Item> newItems = databaseHandler.getItems(); ListArrayAdapter.clear(); ListArrayAdapter.addAll(newItems); ListArrayAdapter.notifyDataSetChanged(); databaseHandler.close(); 

I first cleared the data from the adapter, then added the new collection of items, and only then set notifyDataSetChanged(); This was not clear for me at first, so I wanted to point this out. Take note that without calling notifyDataSetChanged() the view won't be updated.

Answer 2

In my understanding, if you want to refresh ListView immediately when data has changed, you should call notifyDataSetChanged() in RunOnUiThread().

private void updateData() {     List<Data> newData = getYourNewData();     mAdapter.setList(yourNewList);      runOnUiThread(new Runnable() {         @Override         public void run() {                 mAdapter.notifyDataSetChanged();         }     }); }