ListView Duplicates Android

Question

When I get a search result from my table, the results show up twice.

Duplicate Results

The results "a / a", "aa / aa", and "ab / a" are all correct and should be there. However, I don't want the duplicate values in the third listview entry.

Any ideas why this is happening?

Main Screen

// Set up search array
    for(int i = 0; i < isbn.length; i++)
    {
        searchArray.add(new InventoryItem(isbn[i], InventoryAdapter.getTitleAndAuthorByISBN(isbn[i])));
    }
    Toast.makeText(getApplicationContext(), "searchArray.size()="+searchArray.size(), Toast.LENGTH_LONG).show();

    // add data in custom adapter
    adapter = new CustomAdapter(this, R.layout.list, searchArray);
    ListView dataList = (ListView) findViewById(R.id.list);
    dataList.setAdapter(adapter);

CustomAdapter

public class CustomAdapter extends ArrayAdapter<InventoryItem> {
   Context context;
   int layoutResourceId;
   LinearLayout linearMain;
   ArrayList<InventoryItem> data = new ArrayList<InventoryItem>();

   public CustomAdapter(Context context, int layoutResourceId,
                 ArrayList<InventoryItem> data) {
          super(context, layoutResourceId, data);
          this.layoutResourceId = layoutResourceId;
          this.context = context;
          this.data = data;
   }

   @Override
   public View getView(int position, View convertView, ViewGroup parent) {
       View row = convertView;

          if (row == null) {
                 LayoutInflater inflater = ((Activity) context).getLayoutInflater();
                 row = inflater.inflate(layoutResourceId, parent, false);
                 linearMain = (LinearLayout) row.findViewById(R.id.lineraMain);
                 }

                 InventoryItem myItem = data.get(position);
                 TextView label = new TextView(context);
                 label.setText(myItem.details);
                 linearMain.addView(label);

          return row;

   }
}

score 9 · Accepted Answer · edited Aug 02 '18 at 06:35

9

Well, the problem is in your getView(int position, View convertView, ViewGroup parent) method, because you keep adding views to the previously recycled view that listview provides you. Instead of creating a textview dynamically, you should inflate it when you create your view.

For example, to fix this:

    @Override
       public View getView(int position, View convertView, ViewGroup parent) {
           View row = null;

          if (convertView == null) {
                 LayoutInflater inflater = ((Activity) context).getLayoutInflater();
                 row = inflater.inflate(layoutResourceId, parent, false);
                 //Make sure the textview exists in this xml
          } else {
                 row = convertView;
          }

          InventoryItem myItem = data.get(position);
          TextView label = (Textview) row.findViewById(R.id.YOU_TEXT_VIEW_ID);
          label.setText(myItem.details);

          return row;

   }

edited Aug 02 '18 at 06:35

IntelliJ Amiya

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answered Jan 10 '14 at 20:47

Submersed

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Works beautifully. Thanks. – erad Jan 10 '14 at 23:29
how can this work ? there is no `convertView = row` or a `convertView.setTag(row)`. – Siddharth Jun 27 '14 at 11:55
It works because View row is just used as a pointer - convertView and row both end up referencing the same Object. You could in all honesty take out View row = null, the else statement, and replace all "row" variables with convertView and it'd work the same. I posted this answer a while ago, and the above is just how I decided to do it at the time. Also, in the above example there's no need for setting a tag on the view. – Submersed Jun 27 '14 at 14:20

score 0 · Answer 2 · answered Jan 10 '14 at 20:44

0

View are re-used by the adapter. So when you call

linearMain.addView(label);

It is adding multiple views into your list item every time it gets the view.

Do you really need to create a new TextView every time and add it to your list item? I would change this this to just set the text on one existing TextView.

answered Jan 10 '14 at 20:44

Greg Ennis

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can you take look at my code http://stackoverflow.com/q/40145549/6648201 – rookieDeveloper Oct 21 '16 at 06:15

ListView Duplicates Android

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