android - 从 RecyclerAdapter 获取数据

Question

我有一个带 fragment 的抽屉导航。

• 其中一个 fragment 是 WatchListFragment，它包含一个 RecyclerView，其中填充了一个剧集列表。

• list 与 RecyclerAdapter 相连。在 RecyclerAdapter 中，我有一个 onLongClickListener，它的结果应该是更改列表中的某些剧集，并用它替换我在 WatchListFragment 中的列表。

但我不知道如何将数据传递到我的 WatchListFragment。在 c++ 中，id 只是通过引用传递列表，但这在这里不起作用。有任何想法吗？

fragment 代码:

public class WatchListFragment extends Fragment {
private EpisodeRecycleAdapter mAdapter;
private List<Episode> releasedEpisodeList; //contains all unseen & released episodes
private RecyclerView mRecyclerView;
private Context context;

@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    super.onCreateView(inflater, container, savedInstanceState);

View view = inflater.inflate(R.layout.watch_list_fragment, container, false);
context = view.getContext();

mRecyclerView = (RecyclerView) view.findViewById(R.id.watchlistRV);
/* improved performance if size of the layout doesnt change */
mRecyclerView.setHasFixedSize(true);
RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(context);
mRecyclerView.setLayoutManager(mLayoutManager);

//load watchlist from saved file
ejson = new EpisodeJSON(context);
watchList = ejson.readFromFile();

wlFunc = new WatchListFunctions();

//load released episodes of watchlist in releasedEpisodeList
releasedEpisodeList = wlFunc.getReleasedEpisodeList(watchList);
mAdapter = new EpisodeRecycleAdapter(context, releasedEpisodeList);
mRecyclerView.setAdapter(mAdapter);
}

@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
    inflater.inflate(R.menu.watchlist_options, menu);
}

RecyclerAdapter 代码:

class EpisodeRecycleAdapter extends RecyclerView.Adapter<EpisodeRecycleAdapter.ViewHolder> {
private List<Episode> episodes = new ArrayList<>();
private Context mContext;

EpisodeRecycleAdapter(Context context, List<Episode> myDataset) {
    super();
    this.episodes = myDataset;
    mContext = context;
}

// Provide a reference to the views for each data item
// Complex data items may need more than one view per item, and
// you provide access to all the views for a data item in a view holder
static class ViewHolder extends RecyclerView.ViewHolder {
    // each data item is just a string in this case
    TextView textViewName, textViewNumbers, textViewDate;
    ImageView imageViewEye;

    ViewHolder(View v) {
        super(v);
        textViewName = (TextView)v.findViewById(R.id.showname);
        textViewNumbers = (TextView)v.findViewById(R.id.seasonepisodenumbers);
        textViewDate = (TextView)v.findViewById(R.id.date);
        imageViewEye = (ImageView) v.findViewById(R.id.eye_image);
    }
}

// Create new views (invoked by the layout manager)
@Override
public EpisodeRecycleAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    // create a new view
    View v = LayoutInflater.from(parent.getContext())
            .inflate(R.layout.listitem_row, parent, false);

    v.setOnLongClickListener(new View.OnLongClickListener() {
        @Override
        public boolean onLongClick(View view) {
            RecyclerView mRecyclerView = (RecyclerView) view.getRootView().findViewById(R.id.watchlistRV);
            int itemPosition = mRecyclerView.getChildLayoutPosition(view);
            final Episode episodeItem = episodes.get(itemPosition);
            final int interval = episodeItem.getInterval();
            final LocalDate episodeDate = episodeItem.getDate();

            AlertDialog.Builder alert = new AlertDialog.Builder(mContext);
            alert.setTitle("title");
            alert.setMessage("msg");

            String dateStringArray[] = new String[52];
            for (int i = 0; i < 52; i++) {
                dateStringArray[i] = episodeDate.plusDays(interval * (i+1)).toString("dd.MM.yy");
            }
            final Spinner picker = new Spinner(mContext);
            ArrayAdapter<String> adapter = new ArrayAdapter<>(mContext, android.R.layout.simple_spinner_item, dateStringArray);
            adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
            picker.setAdapter(adapter);
            alert.setView(picker);
            alert.show();

            alert.setPositiveButton("Ok", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int whichButton) {
                    int i = 1;
                    int eId = episodeItem.getSeasonID();
                    for(Episode e: episodes){
                        if(e.getSeasonID() == eId && !e.getDate().isBefore(episodeItem.getDate())){
                            e.setDate(e.getDate().plusDays(interval * i));
                            i++;
                        }
                    }
                }
            });
            //TODO get episodes in watchlistfragment

            alert.setNegativeButton("Cancel",
                    new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog, int which) {
                        }
                    });

            return true; //return true so no onClick event happens
        }
    });
    return new ViewHolder(v);
}

// Replace the contents of a view (invoked by the layout manager)
@Override
public void onBindViewHolder(ViewHolder holder, int pos) {
    // - get element from your dataset at this position
    // - replace the contents of the view with that element
    holder.textViewName.setText(episodes.get(pos).getShowName());
    holder.textViewNumbers.setText(episodes.get(pos).getSeasonEpisodeAsString());
    holder.textViewDate.setText(episodes.get(pos).getDateAsString());
}

// Return the size of your dataset (invoked by the layout manager)
@Override
public int getItemCount() {
    return episodes.size();
}

Answer 1

像这样在你的适配器中创建一个方法

public static List<Episode> getList(){
    return episodes ;
}

然后像这样在你的 fragment 中调用这个方法

mAdapter.getList(); // List<Episode> after changes

您可以使用的另一种方法

你可以这样做releasedEpisodeList = episodes;在佛r(Episode e: episodes){ if(e.getSeasonID() == eId && !e.getDate().isBefore(episodeItem.getDate())){ e.setDate(e.getDate().plusDays(interval * i)); i++; } }releasedEpisodeList = episodes;之后为此制作private List<Episode> releasedEpisodeList;进入public static List<Episode> releasedEpisodeList