CODEWITHSUNDEEP
androiddatabaselistviewlarge-data
rezam
rezam

Reputation: 627

loading large database in listview

I have a database with about 12000 records which I want to load in a ListView. I'm using BaseAdapter. When I load items in ListView, It's taking so long.
Is there any way to reduce this time, for example I have seen an app that loads only limited numbers of items until the scroll bar reaches the end of ListView, then it loads again more items.

Upvotes: 1

Views: 8232

Answers (2)

Julian Mancera
Julian Mancera

Reputation: 304

You should set onScrollListener in your list and keep a track of the visibility of the items and the offset. I show you an example here:

// Adapter for the custom list
adapter = new Adapter(this, activityList);
setListAdapter(adapter);
registerForContextMenu(getListView());
getListView().setOnScrollListener(new OnScrollListener(){
    public void onScroll(AbsListView lw, final int firstVisibleItem,
    final int visibleItemCount, final int totalItemCount) {

        switch(lw.getId()) {
            case android.R.id.list:     

                // Make your calculation stuff here. You have all your
                // needed info from the parameters of this function.

                // Sample calculation to determine if the last 
                // item is fully visible.
                final int lastItem = firstVisibleItem + visibleItemCount;
                if(lastItem == totalItemCount) {
                    // Last item is fully visible.
                    Log.i("a", "last item fully visible...");

                    try {
                        if(offset > 0){
                            int newLimit;
                            int oldOffset = offset;
                            if(offset >= limit){
                            newLimit = limit;
                            offset = offset - limit;
                        }
                        else{
                            newLimit = length;
                            offset = 0;
                        }
                        for (int i=0; i < newLimit; i++)
                        {
                            JSONObject item = jFeed.getJSONObject(i + length - oldOffset);
                            // Pulling items from the array

                            // Get list info
                            String sInfo = item.getString(TAG_INFO);
                            Log.i(MainActivity.class.getName(), "Info: " + sInfo);

                            // Populate the dynamic custom list
                            HashMap<String, String> map = new HashMap<String, String>();
                            map.put(KEY_INFO, sInfo);

                            activityList.add(map);
                        }
                        adapter.notifyDataSetChanged();

                    } catch (JSONException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
        }
    }

    public void onScrollStateChanged(AbsListView view, int scrollState) {
        // TODO Auto-generated method stub
        if(scrollState == 0) 
            Log.i("a", "scrolling stopped...");
    }
});

Upvotes: 0

amatellanes
amatellanes

Reputation: 3735

This may be useful, a ListView with load More button:

http://www.androidhive.info/2012/03/android-listview-with-load-more-button/

You can also take a look here:

How can I implement paging in listview in android?

Upvotes: 1

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