c# - NotifyDataSetChanged 不更新我的 ListView

Question

NotifyDataSetChanged() 不会更新我的 ListView，即使我正在重新读取序列化的 xml 文件。它仅在再次调用 oncreate 后更新。阅读一些 Java 代码，它告诉我重新填充我的列表适配器，但这仍然不起作用。有什么想法吗？

public override View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
            {

                View view = inflater.Inflate(Resource.Layout.Card, null);

                listView = view.FindViewById<ListView>(Resource.Id.cardListView);

                return view;
            }


            public override void OnResume()
            {
                base.OnResume();
                List<string> nameList = new List<string>();
                string documentsPath = Android.OS.Environment.ExternalStorageDirectory + "/Gate";
                var cardPath = Path.Combine(documentsPath, "card.xml");

                if (File.Exists(cardPath))
                {
                    XmlSerializer serializer = new XmlSerializer(typeof(List<Card>));
                    StreamReader reader = new StreamReader(cardPath);
                    cardList = (List<Card>)serializer.Deserialize(reader);
                    reader.Close();
                }
                else
                {
                    cardList = new List<Card>();
                }

                foreach (Card card in cardList)
                {
                    nameList.Add(card.name);
                }

                var adapter = new ArrayAdapter<string>(this.Activity, Android.Resource.Layout.SimpleListItem1, nameList);

                listView.Adapter = adapter;

                adapter.NotifyDataSetChanged();
            }

Answer 1

您应该只在 OnCreate 中创建适配器一次并存储它。

然后，在 OnResume() 中，仅使用 adapter.AddAll(nameList) 更新值并调用 NotifyDataSetChanged()；