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
}
});
}
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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
}
}
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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!
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