Question

当用户长按一个listViews元素时，会出现一个新对话框，询问他是否要从数据库中删除该项目。如果是这样，那么在那个对话框片段onCreateDialog方法中，我从数据库中删除项目。这是问题：如何刷新主片段中的listView？

这是我的mainFragment函数来处理ListView：

public void handleNotes（final ListView notesListView）{

if (database.getNoteCount() != 0) {
    notesListView.setAdapter(new NoteAdapter(getActivity(), database.getAllNotes()));

    notesListView.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
        @Override
        public boolean onItemLongClick(AdapterView<?> adapterView, View view, int i, long l) {
            TextView textViewId = (TextView) view.findViewById(R.id.textViewId);

            Toast.makeText(getActivity(), textViewId.getText().toString() + "", Toast.LENGTH_LONG).show();

            DeleteNoteFragment newFragment = new DeleteNoteFragment(database, that, notesListView, Integer.parseInt(textViewId.getText().toString()));
            newFragment.show(getActivity().getSupportFragmentManager(), "deleteConfirmation");

            return false;
        }
    });
}

}

这是onCreateDialog：

public Dialog onCreateDialog(Bundle savedInstanceState) {
    // Use the Builder class for convenient dialog construction
    AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
    builder.setMessage(R.string.dialog_delete_note)
            .setPositiveButton(R.string.dialog_delete_confirm, new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int id) {
                    database.removeNote(i);
                    mainFragment.handleNotes(notesListView);
                    Toast.makeText(getActivity(), "Note deleted successfully!", Toast.LENGTH_LONG).show();
                }
            })
            .setNegativeButton(R.string.dialog_delete_denny, new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int id) {
                    // User cancelled the dialog
                }
            });

    // Create the AlertDialog object and return it
    return builder.create();
}

Answer 1

使用以下代码删除ListAdapter中的项目。

adapter.remove(item);

然后使用以下代码与ListView

一起刷新适配器

adapter.notifyDataSetChanged();

项目从数据库中删除后如何更新listView？

1 个答案: