删除元素后如何刷新ListView？

Question

我已经创建了一个列表视图，但是当我删除一个元素时，它不会刷新。 我努力了

 adapter.notifyDataSetChanged();

和

getListView().invalidateViews();

在主要活动中：

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; } 

有人可以帮我刷新listview吗？ 我想在CustomAdapterOrdini或Ordini.java中的onResume中刷新列表视图。

public void onClick(View v) {

                // HERE I WANT REFRESH MY LISTVIEW

有一个简单的方法吗？ 非常感谢！

Answer 1

您已经在MainActivity声明了ArrayProdotto ，并且正在CustomAdapterOrdini中显示rowItem中的数据。 您必须同时从列表中删除数据并调用notifyDataSetChanged();

像下面的代码。

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）。 从适配器中删除项目：

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

2）。 调用adapter.notifyDataSetChanged();

每次从适配器删除项目时，都应调用notifyDataSetChanged() 。 不仅在onResume 。

请注意，您应该从适配器中删除项目，以更改ListView项目，而不是从存储中更改项目（ ArrayList ， SQLite或其他）。