Question

嗨，我认为我的问题与此notifyDataSetChanged not working on RecyclerView有关我试图从异步任务刷新我的布局，但当我调用通知datasetchange没有任何反应，但如果我创建一个适配器的新实例并调用notifydatasetchanged然后它确实工作香港专业教育学院尝试了一些事无济于事，并想知道我做错了什么，

我像这样引用它

 public ListAdapter cardAdapter;

然后在onCreate中我初始化所有与我的回收器视图有关的事情（这里需要的唯一一点就是我如何初始化我的适配器，但为了清楚起见，添加了与我的回收器视图有关的一切）

   staggeredGridLayoutManagerVertical = new 
   customLinearLayoutManager(this,customLinearLayoutManager.VERTICAL,false);
    recyclerView = (RecyclerView) findViewById(R.id.list_view);
    OnItemTouchListener itemTouchListener = new     
    FinalListActivity.OnItemTouchListener() {
        @Override
        public void onCardClick(View view, int position) {
            //removeAt(position);
            list.remove(position);
            cardAdapter.notifyItemRemoved(position);
        }

        @Override
        public void onCardLongClick(View view, int position) {
            //clearGrid();
        }
    };
    cardAdapter = new ListAdapter(list,this,itemTouchListener);
    recyclerView.setLayoutManager(staggeredGridLayoutManagerVertical);
    recyclerView.setItemAnimator(new DefaultItemAnimator());
    recyclerView.setAdapter(cardAdapter);
    //cardAdapter.notifyDataSetChanged();

    ItemTouchHelper.Callback callback =
            new SimpleItemTouchHelperCallback(cardAdapter);
    mItemTouchHelper = new ItemTouchHelper(callback);
    mItemTouchHelper.attachToRecyclerView(recyclerView);

如果我在这些方法之前向列表中添加项目，那么我的回收站视图会显示信息，但我想要的是获取异步任务中的信息并在onPostExecute中填充列表但是当我调用时

cardAdapter.notifyDataSetChanged();

从onPostExecute没有任何反应，任何帮助？

修改添加适配器

public class ListAdapter extends  
RecyclerView.Adapter<ListAdapter.MyViewHolder> 
implements ItemTouchHelperAdapter{
private List<String> cardMakerList;
private OnStartDragListener mDragStartListener;
private FinalListActivity.OnItemTouchListener onItemTouchListener;

public class MyViewHolder extends RecyclerView.ViewHolder{
    public EditText cardText;
    public ImageView close;
    public ContentLoadingProgressBar progress;
    public ImageView handleView;
    public RelativeLayout cardBack;

    public MyViewHolder(View view){
        super(view);
        cardText = (EditText) view.findViewById(R.id.cardText);
        close = (ImageView) view.findViewById(R.id.close);
        cardBack =(RelativeLayout)view.findViewById(R.id.cardLayout);
        close.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                onItemTouchListener.onCardClick(v, getPosition());
            }
        });
        /*
        close.setOnLongClickListener(new View.OnLongClickListener() {
            @Override
            public boolean onLongClick(View v) {
                onItemTouchListener.onCardLongClick(v, getPosition());
                return true;
            }
        });
        */
        progress = (ContentLoadingProgressBar)  
        view.findViewById(R.id.progress);
        handleView = (ImageView)view.findViewById(R.id.handle);
    }

}
public ListAdapter(List<String> cardMakerList,OnStartDragListener 
dragStartListener,FinalListActivity.OnItemTouchListener onItemTouchListener) 
{
    this.cardMakerList = cardMakerList;
    mDragStartListener = dragStartListener;
    this.onItemTouchListener = onItemTouchListener;
}
@Override
public boolean onItemMove(int fromPosition, int toPosition) {
    if (fromPosition < toPosition){
        for (int i = fromPosition; i < toPosition; i++){
            Collections.swap(cardMakerList,i,i+1);
        }
    }else{
        for (int i = fromPosition; i > toPosition; i--){
            Collections.swap(cardMakerList,i,i-1);
        }
    }
    notifyItemMoved(fromPosition,toPosition);
    return true;
}
@Override
public void onItemDismiss(int position) {
    cardMakerList.remove(position);
    notifyItemRemoved(position);
}
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType){
    View itemView = LayoutInflater.from(parent.getContext())
            .inflate(R.layout.card_view_holder, parent, false);
    return new MyViewHolder(itemView);
}

@Override
public void onBindViewHolder(final MyViewHolder holder, final int position)  
{
    String cardString = cardMakerList.get(position);
    holder.cardText.setText(cardString);
    holder.handleView.setOnTouchListener(new View.OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            if (MotionEventCompat.getActionMasked(event) ==
                    MotionEvent.ACTION_DOWN) {
                mDragStartListener.onStartDrag(holder);
            }
            return false;
        }
    });
    holder.close.setOnTouchListener(new View.OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            //cardMakerList.remove(position);
            return false;
        }
    });
}
@Override
public int getItemCount(){
    return cardMakerList.size();
}
}

Answer 1

可能会出现这种情况的原因有很多，其中一个原因是list变量没有被更新，因为在某些时候它失去了它的主要实例并且适配器不再监听它。在这种情况下，您应该在适配器中实现类似

的方法

public void refreshMyList(List<String> list){
    this.cardMakerList.clear();
    this.cardMakerList.addAll(list);
    this.notifyDataSetChanged();
}

现在，每次要刷新RecyclerView时，只需使用新列表调用此方法。

notifydatasetchanged无法从异步任务工作

1 个答案: