Question

我有一个带有RecyclerView的片段，我想在从IntentService获取一些数据后更新。

服务使用Otto EventBus完成并将数据发送到Fragment。我可以确认原因是我添加了一些日志消息并打印了一些值，例如：dataSet.get(0).getName(). 之后我拨打adapter.notifyDataSetChanged()，但屏幕上没有任何内容。

如果您认为它可以提供帮助，我可以为您提供自定义适配器的代码：

public class FilteredVideoListAdapter extends RecyclerView.Adapter<FilteredVideoListAdapter.ViewHolder> {

public static final String TAG = "FILTEREDVIDEO-ADAPTER";

public List<FilteredVideo> data;
public Context context;

public FilteredVideoListAdapter(List<FilteredVideo> data) {
    this.data = data;

}


public static class ViewHolder extends RecyclerView.ViewHolder {
    TextView tvTitle;
    TextView tvSubtitle;
    ImageView imageView;

    public ViewHolder(View itemView) {
        super(itemView);

        tvTitle = (TextView) itemView.findViewById(R.id.tv_filtered_video_title);
        tvSubtitle = (TextView) itemView.findViewById(R.id.tv_filtered_video_subtitle);
        imageView = (ImageView) itemView.findViewById(R.id.iv_filtered_video_image);
    }

}

@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    context = parent.getContext();
    View v = LayoutInflater.from(parent.getContext())
            .inflate(R.layout.item_filtered_video, parent, false);

    return new ViewHolder(v);
}

@Override
public void onBindViewHolder(ViewHolder viewHolder, int position) {
    viewHolder.tvTitle.setText(data.get(position).getName());
    viewHolder.tvSubtitle.setText(data.get(position).getDataUrl());

    int dimen = context.getResources().getDimensionPixelSize(R.dimen.filtered_video_image_size);

    Picasso.with(context)
            .load(data.get(position).getThumbnailUrl())
            .resize(dimen, dimen)
            .into(viewHolder.imageView);
}

@Override
public int getItemCount() {
    return data.size();
}

}

Fragment类的代码：

public class FilteredVideoListFragment extends BaseFragment {

private static final String TAG = "FILTEREDVLIST-FRAGMENT";
public RecyclerView recyclerView;

protected FilteredVideoListAdapter adapter;
protected RecyclerView.LayoutManager layoutManager;

public List<FilteredVideo> dataSet;

//first time there aren't any populated data
private boolean datasetIsNull = true;

public static FilteredVideoListFragment newInstance() {
    return new FilteredVideoListFragment();
}

@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    dataSet = new ArrayList<>();

    BusProvider.getInstance().register(this);

    // startService here -
    Intent intentService = new Intent(activity, GetMostPopularIntentService.class);
    activity.startService(intentService);
}

@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_filtered_video_list, container, false);

    recyclerView = (RecyclerView) view.findViewById(R.id.rv_filtered_video_list);

    recyclerView.setHasFixedSize(true);
    recyclerView.addItemDecoration(new DividerItemDecoration(getActivity(),
            DividerItemDecoration.VERTICAL_LIST));

    layoutManager = new LinearLayoutManager(getActivity());
    recyclerView.setLayoutManager(layoutManager);

    adapter = new FilteredVideoListAdapter(dataSet);
    recyclerView.setAdapter(adapter);

    return view;
}

private BroadcastReceiver mostpopularReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        String resultCode = intent.getStringExtra("resultCode");
        if ("OK".equals(resultCode)) {
            Toast.makeText(activity, "Most Popular Results Received!", Toast.LENGTH_SHORT).show();
        }
    }
};

/** Register/ unRegister Receiver */
@Override
public void onResume() {
    super.onResume();
    IntentFilter intentFilter = new IntentFilter(GetMostPopularIntentService.ACTION);
    LocalBroadcastManager.getInstance(activity).registerReceiver(mostpopularReceiver, intentFilter);
}

@Override
public void onPause() {
    super.onPause();
    LocalBroadcastManager.getInstance(activity).unregisterReceiver(mostpopularReceiver);
}

/**
 * Receives Event from GetMostPopularIntentService when data retrieved
 * successfully.
 */
@Subscribe
public void onMostPopularReceivedEvent(MostPopularReceivedEvent event) {
    Log.i(TAG, "clickevent ");

    dataSet = event.getFilteredVideoList();
    Log.i(TAG, "NOTIFY ADAPTER SIZE == " + dataSet.size() );
    Log.i(TAG, "NOTIFY ADAPTER SIZE == " + dataSet.get(0).getName() );
    adapter.notifyDataSetChanged();
    Log.i(TAG, "AFTER NOTIFY ADAPTER ");
}

@Subscribe
public void onToastRequest(ToastRequest request) {
    Log.i(TAG, "onToastRequest ");
    Toast.makeText(activity, request.message, request.duration).show();
}

}

Answer 1

尝试 -

@Subscribe
public void onMostPopularReceivedEvent(MostPopularReceivedEvent event) {

    adapter = new FilteredVideoListAdapter(event.getFilteredVideoList());
    recyclerView.setAdapter(adapter);
}

Answer 2

试试这个适配器

public class FilteredVideoListAdapter extends RecyclerView.Adapter<FilteredVideoListAdapter.ViewHolder> {

    public static final String TAG = "FILTEREDVIDEO-ADAPTER";

    public List<FilteredVideo> data;
    public Context mContext;

    public FilteredVideoListAdapter(Context context, List<FilteredVideo> data) {
        this.data = data;
        this.mContext = context;

    }

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
        View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.item_filtered_video, null);

        return new ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(ViewHolder customViewHolder, int i) {
        FilteredVideo filteredVideo = data.get(i);

        customViewHolder.tvTitle.setText(filteredVideo.getName());
        customViewHolder.tvSubtitle.setText(filteredVideo.getDataUrl());

        int dimen = mContext.getResources().getDimensionPixelSize(R.dimen.filtered_video_image_size);

        Picasso.with(mContext)
                .load(filteredVideo.getThumbnailUrl())
                .resize(dimen, dimen)
                .into(customViewHolder.imageView);
    }

    @Override
    public int getItemCount() {
        return (null != data ? data.size() : 0);
    }

}

并像你一样打电话给你的片段

@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_filtered_video_list, container, false);

    recyclerView = (RecyclerView) view.findViewById(R.id.rv_filtered_video_list);

    recyclerView.setHasFixedSize(true);
    recyclerView.addItemDecoration(new DividerItemDecoration(getActivity(),
            DividerItemDecoration.VERTICAL_LIST));

    layoutManager = new LinearLayoutManager(getActivity());
    recyclerView.setLayoutManager(layoutManager);

    adapter = new FilteredVideoListAdapter(getActivity(), dataSet);
    recyclerView.setAdapter(adapter);

    return view;
}

RecyclerView适配器notifyDataSetChanged不起作用

2 个答案: