java - 为什么用相同的数据填充 RecyclerView 行？

Question

我正在尝试使用存储在 ArrayList 中的数据来填充 RecyclerView。当 RecyclerView 加载每条数据时，每行重复 4 次。

我尝试了各种解决方案，但似乎都无法解决问题。

在对“mData”中的数据进行一些调试之后，似乎是正确的，所以这会让我相信这个问题是“onBindViewHolder”？

适配器

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

private List<String> mData;
private LayoutInflater mInflater;
private ItemClickListener mClickListener;

// data is passed into the constructor
public EventsRecyclerViewAdapter(List<String> data) {
    this.mInflater = LayoutInflater.from(MainActivity.mainActivity);
    this.mData = data;
}

// inflates the row layout from xml when needed
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View view = mInflater.inflate(R.layout.recyclerview_row, parent, false);
    return new ViewHolder(view);
}

// binds the data to the TextView in each row
@Override
public void onBindViewHolder(ViewHolder holder, int position) {

    holder.keyID.setText(mData.get(position));
    holder.lockID.setText(mData.get(position));
    holder.eventTime.setText(mData.get(position));
    holder.eventType.setText(mData.get(position));
}

// total number of rows
@Override
public int getItemCount() {
    return mData.size();
}


// stores and recycles views as they are scrolled off screen
public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
    TextView keyID;
    TextView lockID;
    TextView eventTime;
    TextView eventType;

    ViewHolder(View itemView) {
        super(itemView);
        keyID = itemView.findViewById(R.id.keyIDTV);
        lockID = itemView.findViewById(R.id.lockIDTV);
        eventTime = itemView.findViewById(R.id.eventDateTV);
        eventType = itemView.findViewById(R.id.eventTypeTV);
        itemView.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        if (mClickListener != null) mClickListener.onItemClick(view, getAdapterPosition());
    }
}




// parent activity will implement this method to respond to click events
public interface ItemClickListener {
    void onItemClick(View view, int position);
}

fragment

 public class KeyEvents extends Fragment {


    public static KeyInfo newInstance() {
        KeyInfo fragment = new KeyInfo();
        return fragment;
    }

    EventsRecyclerViewAdapter adapter;

    ArrayList<String> eventsList;


    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        EventsOperationHandler ev = new EventsOperationHandler();

        eventsList = new ArrayList<>();

        for (int i=0; i<ev.getEvents().size(); i++) {

            eventsList.add(ev.getEvents().get(i).get(0));
            eventsList.add(ev.getEvents().get(i).get(1));
            eventsList.add(ev.getEvents().get(i).get(2));
            eventsList.add(ev.getEvents().get(i).get(3));
        }
    }

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


        RecyclerView recyclerView = view.findViewById(R.id.rvEvents);
        recyclerView.setLayoutManager(new LinearLayoutManager(MainActivity.mainActivity));
        adapter = new EventsRecyclerViewAdapter(eventsList);

        recyclerView.setAdapter(adapter);
        return view;
    }


}

Answer 1

在你的 'onBindViewHolder' 中，你在你的每个 textView 中设置相同的数据

// binds the data to the TextView in each row
@Override
public void onBindViewHolder(ViewHolder holder, int position) {

    holder.keyID.setText(mData.get(position));
    holder.lockID.setText(mData.get(position));
    holder.eventTime.setText(mData.get(position));
    holder.eventType.setText(mData.get(position));
}

在这里，您要为 holder 中的每个 textView 设置 mData.get(position)

---

一个解决方案是为你的 recyclerView 创建一个 Pojo 类

Create Pojo Event class

class Event{
    public String keyID;
    public String lockID;
    public String eventTime;
    public String eventType;
}

Create a list of 'Event' in your fragment

public class KeyEvents extends Fragment {


    public static KeyInfo newInstance() {
        KeyInfo fragment = new KeyInfo();
        return fragment;
    }

    EventsRecyclerViewAdapter adapter;

    ArrayList<Event> eventsList;


    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        EventsOperationHandler ev = new EventsOperationHandler();

        eventsList = new ArrayList<>();

        for (int i=0; i<ev.getEvents().size(); i++) {
            Event event = new Event();

            event.keyID = ev.getEvents().get(i).get(0);
            event.lockID = ev.getEvents().get(i).get(1);
            event.eventTime = ev.getEvents().get(i).get(2);
            event.eventType = ev.getEvents().get(i).get(3);

            eventsList.add(event);
        }
    }

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


        RecyclerView recyclerView = view.findViewById(R.id.rvEvents);
        recyclerView.setLayoutManager(new LinearLayoutManager(MainActivity.mainActivity));
        adapter = new EventsRecyclerViewAdapter(eventsList);

        recyclerView.setAdapter(adapter);
        return view;
    }


}

Modify your recyclerView to handle to 'Event' class

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

private List<Event> mData;
private LayoutInflater mInflater;
private ItemClickListener mClickListener;

// data is passed into the constructor
public EventsRecyclerViewAdapter(List<Event> data) {
    this.mInflater = LayoutInflater.from(MainActivity.mainActivity);
    this.mData = data;
}

// inflates the row layout from xml when needed
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View view = mInflater.inflate(R.layout.recyclerview_row, parent, false);
    return new ViewHolder(view);
}

// binds the data to the TextView in each row
@Override
public void onBindViewHolder(ViewHolder holder, int position) {
    Event event = mData.get(position);
    holder.keyID.setText(event.keyID);
    holder.lockID.setText(event.lockId);
    holder.eventTime.setText(event.eventTime);
    holder.eventType.setText(event.eventType);
}

// total number of rows
@Override
public int getItemCount() {
    return mData.size();
}


// stores and recycles views as they are scrolled off screen
public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
    TextView keyID;
    TextView lockID;
    TextView eventTime;
    TextView eventType;

    ViewHolder(View itemView) {
        super(itemView);
        keyID = itemView.findViewById(R.id.keyIDTV);
        lockID = itemView.findViewById(R.id.lockIDTV);
        eventTime = itemView.findViewById(R.id.eventDateTV);
        eventType = itemView.findViewById(R.id.eventTypeTV);
        itemView.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        if (mClickListener != null) mClickListener.onItemClick(view, getAdapterPosition());
    }
}




// parent activity will implement this method to respond to click events
public interface ItemClickListener {
    void onItemClick(View view, int position);
}

就是这样，这应该可以完美地工作。