Question

I have implemented a list view, every user scroll to bottom screen, it auto add new data to list view
Once the scroll has completed, onScroll() call for every new item that enters the displaying view, from the beginning to the end of the scrolling.

lv_best = (ListView) findViewById(R.id.lv_best);
bestadapter = new LazyAdapter(this, lst_tab_best);
lv_best.setAdapter(bestadapter);
lv_best.setOnScrollListener(new AbsListView.OnScrollListener() {

    @Override
    public void onScrollStateChanged(AbsListView view, int scrollState) { }

    @Override
    public void onScroll(AbsListView view, int firstVisibleItem,
                        int visibleItemCount, int totalItemCount) {

    Log.d("onScroll ", firstVisibleItem+"-"+visibleItemCount+"-"+totalItemCount);
    boolean loadMore = firstVisibleItem + visibleItemCount >= totalItemCount;
    if(loadMore){
            new ChangeTab_best().execute();
     }
     }
    });

I run in emulator, list above display with 5 items
but I can’t detect the end of scrolling in a ListView, ChangeTab_best() is called many time.When I see Logcat android , all variables firstVisibleItem,visibleItemCount,totalItemCount always equal 0

So what’s happen here?

Answer 1

To detect the item at the bottom of the screen you have to work with firstVisibleItem and visibleItemCount. I had created a demo example for the same using AsyncTask that will loading items in background and update the UI.

Total of firstVisibleItem and visibleItemCount will give you the number of items that are loaded and then you can implement the logic of loading more items.

int loadedItems = firstVisibleItem + visibleItemCount;