Displaying 100,000 objects in ListView from SQLite database

I am trying to display all items from a pre-populated database (with over 100,000 rows) in a ListView using cursors. It works, but it takes a few minutes to start the app and display the ListView. Is there a faster way? I read something about FTS3 tables, does this help?

I am using ArrayList<HashMap<String, String>>

with SimpleAdapter and a custom two line layout. Code:

Cursor cursor = sDictionary.query("FTSgesla", new String[] {PodatkovnaBaza.KEY_WORD, PodatkovnaBaza.KEY_DEFINITION}, null, null, null, null, PodatkovnaBaza.KEY_WORD);

    if (cursor == null) 
    {

            // There are no results
            mTextView.setText("Empty");
    } 
    else 
    {

        HashMap<String, String> item;

        if(cursor.moveToFirst())
        {
            do
            {
                item = new HashMap<String, String>();
                item.put("line1", cursor.getString(0));
                item.put("line2", cursor.getString(1));
                list.add(item);
            }
            while(cursor.moveToNext());
        }

            sa = new SimpleAdapter(GlavniActivity.this, list,
                    R.layout.result,
                    new String[] { "line1","line2" },
                    new int[] {R.id.word, R.id.definition});

            mListView.setAdapter(sa);
            // Define the on-click listener for the list items
            mListView.setOnItemClickListener(new OnItemClickListener() {

                @Override
                public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                   //do something
                }
            });
        }

      

+3


source to share


4 answers


There is no faster way to download 100,000 items, and your user also won't need to see everything at once, hence download them one by one using a stream.



    private class SQLTask extends AsyncTask<Integer, String[], Integer> {

    @Override
    protected Integer doInBackground(Integer... params) {
        db.open();
        Cursor c = db.getAllDataCursor();
        for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext()) {
            String[] temp = new String[c.getColumnCount()];
            for (int i = 0; i < temp.length; i++) {
                temp[i] = c.getString(i);
            }
            publishProgress(thisTask, temp);
        }
        c.close();
        db.close();
    }

    @Override
    protected void onProgressUpdate(String[]... values) {
        super.onProgressUpdate(values);
        // LOAD ONE ROW
    }
}

      

+7


source


It should be in sections with some kind of filtering, loading that many elements just seem excessive.



0


source


I'm not very sure, but I'm afraid your problem is that you are downloading 100,000 views at the same time. Personally, I would use an ArrayAdapter or a base adapter, override the getView (..) method and of course with the ViewHolder template.

Here you have a very smooth and fast example using BaseAdapter: https://github.com/Jachu5/RSS_Feeder_Android/tree/master/RssFeeder_sherlock/src/com/example/adapter

Hope it helps!

0


source


Why are you loading 100k items into a list? Listview is a display element that the user will interact with. Nobody will ever scroll 100K items. Nobody will be able to scroll 1% of this. The answer here is don't download them all.

0


source







All Articles