android-RecyclerView每隔几个项目都是相同的-展开式项目

我对recyclerView有问题.我正在使用此布局在recyclerView：https://github.com/AAkira/ExpandableLayout中扩展cardView.

如果我单击某个项目将其展开,然后向下滚动,则第7个元素也会被展开.我该怎么做才能停止这种影响？我知道这是因为recyclerView会记住视图持有者的状态,并且onBindiewHolder方法中的mIsViewExpanded设置为每第7个项目为true.预先感谢您提供任何解决方案！

这是我的观看者的代码：

class EventsViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {

    private ImageView edit, cancel, expandIcon;

    private ExpandableLayout expandableArea;
    private boolean mIsViewExpanded = false;

    public EventsViewHolder(View itemView) {
        super(itemView);
        expandIcon = (ImageView) itemView.findViewById(R.id.card_item_expand_icon);
        expandIcon.setOnClickListener(this);
        //divider = (View) itemView.findViewById(R.id.event_card_divider);
    }

    private void collapseArea(){
        expandableArea.collapse();
        edit.setVisibility(View.GONE);
        cancel.setVisibility(View.GONE);
        mIsViewExpanded = false;
        expandIcon.setImageResource(R.drawable.vector_drawable_ic_expand_more_black___px);
    }

    private void expandArea(){
        expandableArea.expand();
        edit.setVisibility(View.VISIBLE);
        cancel.setVisibility(View.VISIBLE);
        mIsViewExpanded = true;
        expandIcon.setImageResource(R.drawable.vector_drawable_ic_expand_less_black___px);
    }

    @Override
    public void onClick(View view) {
        if(mIsViewExpanded){
            collapseArea();
            isItemExpanded[getAdapterPosition()] = false;
        }
        else {
            expandArea();
            isItemExpanded[getAdapterPosition()] = true;
        }
    }
}

当我单击CardView中的图标时,expandableArea会根据mIsViewExpanded值而扩展或崩溃.

编辑.
适配器代码：

public class EventsRecyclerViewAdapter extends RecyclerView.Adapter<EventsRecyclerViewAdapter.EventsViewHolder> implements PopupMenu.OnMenuItemClickListener, PopupMenu.OnDismissListener {

public interface EventsRecyclerViewAdapterInterface {
    public void emptyAdapter();

    public void itemDeleted(int id);
}

private List<Event> listData = new ArrayList<>();
private LayoutInflater inflater;
private MainActivity context;
private View view;
private int positionToCancel;

private boolean[] isItemExpanded;

private EventsRecyclerViewAdapterInterface deleteListener;

@Override
public boolean onMenuItemClick(MenuItem menuItem) {
    removeItem(positionToCancel);
    return true;
}

@Override
public void onDismiss(PopupMenu menu) {
    menu.dismiss();
}


public EventsRecyclerViewAdapter(Activity context, EventsRecyclerViewAdapterInterface deleteListener) {
    this.inflater = LayoutInflater.from(context);
    this.context = (MainActivity) context;
    this.deleteListener = deleteListener;
}

@Override
public EventsViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    view = inflater.inflate(R.layout.item_event_card, parent, false);
    return new EventsViewHolder(view);
}

@Override
public void onBindViewHolder(EventsViewHolder holder, int position) {
    Event item = listData.get(position);

    if(!isItemExpanded[position]){
        if(holder.mIsViewExpanded){
            holder.collapseArea();
        }
    }
    else {
        holder.expandArea();
    }

    holder.title.setText(item.getName());
    holder.place.setText(item.getLocation());

    DateTimeFormatter formatter = DateTimeFormat.forPattern(StaticValues.DATE_TIME_PATTERN_FOR_VIEW);
    holder.time.setText(formatter.print(item.getDate()));

    holder.edit.setOnClickListener(view1 -> takeDetailsEvent(item));
    holder.cancel.setOnClickListener(view1 -> {
        positionToCancel = position;

        MyPopupMenu popup = new MyPopupMenu(view1.getContext(), view1, context);
        popup.inflate(R.menu.event_delete_menu);
        popup.setOnMenuItemClickListener(this);
        popup.setOnDismissListener(this);
        popup.show();
    });

    holder.container.setOnClickListener(view1 -> {
        Intent intent = new Intent(view1.getContext(), EventDetailsActivity.class);
        intent.putExtra("eventId", item.getApiId());
        view1.getContext().startActivity(intent);
    });
}

private void removeItem(int position) {
    deleteListener.itemDeleted(listData.get(position).getApiId());
    listData.remove(position);
    notifyDataSetChanged();

    if (getItemCount() == 0) {
        deleteListener.emptyAdapter();
    }
}

private void takeDetailsEvent(Event event) {
    Intent intent = new Intent(view.getContext(), CreateEventActivity.class);
    intent.putExtra("id", event.getApiId());
    view.getContext().startActivity(intent);
}

public void setListData(List<Event> eventList) {
    listData = eventList;
    isItemExpanded = new boolean[listData.size()];
    notifyDataSetChanged();
}

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

}

我现在就是这样处理的.在适配器类中,我有一个布尔数组,其长度与listData相同.在与列表项相对应的位置上,我保留值：展开时为true,折叠时为false.在onBindViewHolder中,我检查位置是否展开,如果不展开,则将其折叠.这不是理想的解决方案,因为在滚动过程中项目会崩溃,而且看起来也不好.

解决方法:

RecyclerView不会创建新视图,而是会在滚动时重新使用现有视图(ScrappedViews).所以发生的事是当您扩展CardView并滚动时,由于CardView被重用,您将获得另一个扩展视图.

因此,只需在Adapter的onBindView()中折叠/展开视图,因为您需要将状态与适配器列表中的每个项目相关联.

要在滚动过程中解决扩展/折叠动画,只需设置setDuration(0),它使您可以扩展/折叠而没有任何延迟或动画,从而获得更流畅的滚动体验.

标签：android-recyclerview,expandablelistview,android
来源： https://codeday.me/bug/20191026/1938904.html