How to refresh ListView after deleting element?

Question

I have created a listview but when i delete a element, it doesn't refresh. I have tried

 adapter.notifyDataSetChanged();

and

getListView().invalidateViews();

in mainactivity:

case R.id.ordini:

                    Ordini O = new Ordini();
                    android.app.FragmentManager fragmentManager0 = getFragmentManager();
                    android.app.FragmentTransaction fragmentTransaction0 = fragmentManager0
                            .beginTransaction();

                    fragmentTransaction0.replace(R.id.frame, O);
                    fragmentTransaction0.commit();

• Ordini.java

  public class Ordini extends ListFragment implements AdapterView.OnItemClickListener {
  
  int ArraySize;
  CustomAdapterOrdini adapter;
  private List<RowItemOrdini> rowItems;
  Button SendButton;
  
  @Override
  public View onCreateView(LayoutInflater inflater, ViewGroup container,
                           Bundle savedInstanceState) {
  
      return inflater.inflate(R.layout.ordini, null, false);
  
  }
  
  @Override
  public void onActivityCreated(Bundle savedInstanceState) {
  
      super.onActivityCreated(savedInstanceState);
  
      ArraySize = MainActivity.ArrayProdotto.size();
      SendButton = (Button) getActivity().findViewById(R.id.send_btn);
  
      rowItems = new ArrayList<RowItemOrdini>();
  
      for (int i = 0; i < ArraySize; i++) {
          RowItemOrdini items = new RowItemOrdini(
                  MainActivity.ArrayProdotto.get(i),
                  R.drawable.ic_delete_black_24dp,
                  MainActivity.ArrayCode.get(i),
                  MainActivity.ArrayPrezzo.get(i),
                  MainActivity.ArrayColli.get(i),
                  MainActivity.ArrayQuantita.get(i));
  
          rowItems.add(items);
      }
  
      adapter = new CustomAdapterOrdini(getActivity(), rowItems);
      setListAdapter(adapter);
  
      getListView().setOnItemClickListener(this);
  
  
      SendButton.setOnClickListener(new View.OnClickListener() {
          @Override
          public void onClick(View v) {
              Toast.makeText(getActivity(), "invio ordine in corso... ", Toast.LENGTH_SHORT)
                      .show();
              SendOrdine();
          }
      });
  }
  @Override
  public void onResume(){
      super.onResume();
      adapter.notifyDataSetChanged();
      getListView().invalidateViews();
  }
  

• CustomAdapterOrdini

  public class CustomAdapterOrdini extends BaseAdapter {
  
  Context context;
  List<RowItemOrdini> rowItem;
  
  ImageView  Del;
  TextView Colli, Prezzo, Quantita, Code, Product;
  
  
  
  
  CustomAdapterOrdini(Context context, List<RowItemOrdini> rowItem) {
      this.context = context;
      this.rowItem = rowItem;
  
  }
  
  @Override
  public int getCount() {
  
      return rowItem.size();
  }
  
  @Override
  public Object getItem(int position) {
  
      return rowItem.get(position);
  }
  
  @Override
  public long getItemId(int position) {
  
      return rowItem.indexOf(getItem(position));
  }
  @Override
  public boolean  areAllItemsEnabled() {
      return false;
  }
  
  @Override
  public boolean isEnabled(int position) {
      return false;
  }
  
  
  
  
  @Override
  public View getView(int position, View convertView, ViewGroup parent) {
  
      if (convertView == null) {
          LayoutInflater mInflater = (LayoutInflater) context
                  .getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
          convertView = mInflater.inflate(R.layout.list_ordini, null);
      }
      Code = (TextView) convertView.findViewById(R.id.prodcode);
      Product = (TextView) convertView.findViewById(R.id.PRODOTTO);
      Del = (ImageView) convertView.findViewById(R.id.del);
  
      Colli = (TextView) convertView.findViewById(R.id.T1);
      Prezzo = (TextView) convertView.findViewById(R.id.T2);
      Quantita = (TextView) convertView.findViewById(R.id.T3);
  
  
      Del.setFocusable(true);
      Del.setClickable(true);
  
      Del.setTag(convertView);
  
      final RowItemOrdini row_pos = rowItem.get(position);
      // setting the image resource and title
      Del.setImageResource(R.drawable.ic_delete_black_24dp);
      Product.setText(row_pos.getTitle());
      Code.setText(row_pos.getCode());
  
      Colli.setText(row_pos.getColli());
      Prezzo.setText(row_pos.getPrezzo());
      Quantita.setText(row_pos.getQuantita());
  
      Del.setOnClickListener(new View.OnClickListener() {
          @Override
          public void onClick(View v) {
  
              // HERE I WANT REFRESH MY LISTVIEW
  
              MainActivity.ArrayQuantita.remove(0);
              MainActivity.ArrayCode.remove(0);
              MainActivity.ArrayProdotto.remove(0);
              MainActivity.ArrayColli.remove(0);
              MainActivity.ArrayPrezzo.remove(0);
  
              CustomAdapter.ShowDialog("Elemento eliminato con successo!", context);
  
          }
      });
  
      return convertView;
  
  }
  

Can someone help me with listview refresh? I want refresh my listview in CustomAdapterOrdini or in onResume in Ordini.java.

public void onClick(View v) {

                // HERE I WANT REFRESH MY LISTVIEW

There is a simple way? Thank you so much!

Answer 1

You have declare ArrayProdotto in your MainActivity and you are display your data from rowItem in CustomAdapterOrdini. You have to remove your data from both list and call notifyDataSetChanged();

Like as below code.

Del.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {

         // HERE I WANT REFRESH MY LISTVIEW
         MainActivity.ArrayProdotto.remove(position); //Delete from main source
         rowItem.remove(position) // Delete from adapter
         CustomAdapter.ShowDialog("Elemento eliminato con successo!", context);
         notifyDataSetChanged(); // Refresh Adapter

    }
});

Answer 2

1). Remove your item from adapter:

adapter.remove(adapter.getItem(position));

2). Call adapter.notifyDataSetChanged();

You should call notifyDataSetChanged() every time when you deleting item from adapter. Not only in onResume.

Note, that you should remove item from adapter, to change ListView items, not from storage(ArrayList, SQLite, or else).