Android dynamic loading list view onScrollListener issues

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

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;

Answer 2

The above implementaion may cause errors at edge conditions. The sum of first visible item & items in page may be 1 count more or less than expected. I was using the same thing untill i switched to a new method. What i did was implemented a listener to the Adapter of listview and in the getview check if(position== totalItemCount of items in array to be displayed), if yes i call up my listener from adapter. Quite simple

Answer 3

    lv_best.setOnScrollListener(new OnScrollListener() {
                @Override
                public void onScrollStateChanged(AbsListView view, int scrollState) {
                    switch (scrollState) {
                    case OnScrollListener.SCROLL_STATE_IDLE:
                                         // when list scrolling stops

                                        manipulateWithVisibleViews(view);

                        break;
                    case OnScrollListener.SCROLL_STATE_TOUCH_SCROLL:
                        break;
                    case OnScrollListener.SCROLL_STATE_FLING:
                        break;
                    }
                }

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

private void manipulateWithVisibleViews(AbsListView view){
        int count = view.getChildCount(); // visible views count
        int lastVisibleItemPosition = view.getLastVisiblePosition();

        for (int i = 0; i < count; i++) {
            View convertView = view.getChildAt(i);
            // update views
            }
        }

}