android - fragment 是否可以扩展 fragment ？

Question

我是移动开发的新手，我不确定这是否可行。我有一个带有显示内容的回收 View 的 fragment 。问题是其他 fragment 也使用具有相同设计的 Recycler View。是否可以扩展该 fragment ，然后仅通过更改 TextView 和图像来重用其中的所有内容？

fragment 代码:

using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using System.Json;
using Android.Support.V4.App;
using Android.Content;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Android.OS;
using Android.Support.V7.Widget;
using Android.Graphics;
using Homecheck.Adapters;
using Homecheck.Models;
using Newtonsoft.Json;

namespace Homecheck.Fragments {
    public class SmokeSensor : Fragment {
        private RecyclerView recyclerView;
        private RecyclerView.Adapter adapter;
        private RecyclerView.LayoutManager layoutManager;
        private List<ItemData> itemData;
        private ISharedPreferences pref;
        private SessionManager session;
        private DeviceModel deviceModel;
        private string cookie;
        private const string URL_SMOKE_DATA = "http://10.1.1.20/appapi/getsmokedata";

        public async override void OnStart() {
            base.OnStart();

            session = new SessionManager();
            pref = Activity.GetSharedPreferences("UserSession", FileCreationMode.Private);
            cookie = pref.GetString("PHPSESSID", string.Empty);
            var jsonFetcher = new JsonFetcher();
            JsonValue jsonDashboard = await jsonFetcher.FetchJsonAsync(URL_SMOKE_DATA, null, null, cookie);
            deviceModel = new DeviceModel();
            deviceModel = JsonConvert.DeserializeObject<DeviceModel>(jsonDashboard);

            AddSmokeData();

            adapter = new ViewAdapter(itemData);

            new System.Threading.Thread(new System.Threading.ThreadStart(() => {
                Activity.RunOnUiThread(() => {
                    recyclerView.SetAdapter(adapter);
                });
            })).Start();
        }

        public void AddSmokeData() {
            itemData = new List<ItemData>();

            foreach (SensorData sensorData in deviceModel.SensorData) {
                if (sensorData.Value == "1") {
                    itemData.Add(new ItemData() {
                        title = GetString(Resource.String.smoke_detected_text),
                        date = sensorData.Timestamp,
                        image = Resource.Drawable.smoke_red,
                    });
                }
            }
        }

        public override View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
            View view = inflater.Inflate(Resource.Layout.SmokeSensor, container, false);
            recyclerView = view.FindViewById<RecyclerView>(Resource.Id.smoke_recycler_view);
            recyclerView.HasFixedSize = true;
            layoutManager = new StaggeredGridLayoutManager(3, StaggeredGridLayoutManager.Vertical);

            recyclerView.SetLayoutManager(layoutManager);
            recyclerView.SetItemAnimator(new DefaultItemAnimator());
            recyclerView.AddItemDecoration(new SpaceItemDecoration(20));

            return view;
        }

        public class SpaceItemDecoration : RecyclerView.ItemDecoration {
            private int space;

            public SpaceItemDecoration(int space) {
                this.space = space;
            }

            public override void GetItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
                outRect.Left = space;
                outRect.Right = space;
                outRect.Bottom = space;

                if (parent.GetChildAdapterPosition(view) == 0) {
                    outRect.Top = space;
                }
            }
        }

        public class ViewAdapter : RecyclerView.Adapter {
            private List<ItemData> itemData;
            private TextView titleText;
            private TextView dateText;
            private ImageView imageId;

            public ViewAdapter(List<ItemData> itemData) {
                this.itemData = itemData;
            }

            public class ItemView : RecyclerView.ViewHolder {
                public View mainView { get; set; }

                public TextView title { get; set; }

                public TextView date { get; set; }

                public ImageView image { get; set; }

                public ItemView(View view) : base(view) {
                    mainView = view;
                }
            }

            public override RecyclerView.ViewHolder OnCreateViewHolder(ViewGroup parent, int viewType) {
                View itemLayoutView = LayoutInflater.From(parent.Context).Inflate(Resource.Layout.SmokeSensorItems, null);

                titleText = itemLayoutView.FindViewById<TextView>(Resource.Id.item_title);
                dateText = itemLayoutView.FindViewById<TextView>(Resource.Id.item_date);
                imageId = itemLayoutView.FindViewById<ImageView>(Resource.Id.item_icon);

                var viewHolder = new ItemView(itemLayoutView) { title = titleText, date = dateText, image = imageId };

                return viewHolder;
            }

            public override void OnBindViewHolder(RecyclerView.ViewHolder viewHolder, int position) {
                ItemView itemHolder = viewHolder as ItemView;

                itemHolder.title.Text = itemData[position].title;
                itemHolder.date.Text = itemData[position].date;
                itemHolder.image.SetImageResource(itemData[position].image);
            }

            public override int ItemCount {
                get { return itemData.Count; }
            }
        }

        public class ItemData {
            public string title { get; set; }

            public string date { get; set; }

            public int image { get; set; }
        }
    }
}

Answer 1

我已经改变了这个答案，你可以扩展 fragment 。我以前从未见过它完成，但我刚刚玩过，效果很好。我只是认为我从来没有遇到过扩展整个 fragment 有意义的情况，我倾向于认为如果某些东西在多个类中具有实用性，我会把它放在另一个类中。

Jame Gosling(制作 java 的负责人)说不要使用继承作为实现代码重用的手段。

更多信息:http://www.javaworld.com/article/2073649/core-java/why-extends-is-evil.html