使用Snackbar.Callback撤销删除操作

Question

我有一个工作线性RecyclerView通过滑动删除，一切都很好。 但是，当我尝试使用Snackbar.Callback创建“撤消”动作时，出现列表错误，如“无效索引”，该项目被刷掉，然后立即再次出现，甚至出现“不一致检测”错误。任何人在代码中看到奇怪的东西？

 @Override 
     public void onSwiped(final RecyclerView.ViewHolder viewHolder, int direction) { 
      // item position 
      final int pos = viewHolder.getAdapterPosition(); 
      communicator.remove(pos); 
      recyclerViewAdapter.notifyItemRemoved(pos); 

      Snackbar.make(view, R.string.notice_removed, Snackbar.LENGTH_LONG) 
        .setCallback(new Snackbar.Callback() { 
         @Override 
         public void onDismissed(Snackbar snackbar, int event) { 
          switch (event) { 
           case Snackbar.Callback.DISMISS_EVENT_ACTION: 
            recyclerViewAdapter.notifyItemInserted(pos); 
            break; 
           default: 
            communicator.remove(pos); 
            break; 
          } 
         } 
        }) 
        .setAction(R.string.action_undo, new View.OnClickListener() { 
         @Override 
         public void onClick(View v) { 
          // do nothing 
         } 
        }) 
        .show(); 

      recyclerViewAdapter.notifyItemRangeChanged(pos, recyclerViewAdapter.getItemCount()); 
     } 

Answer 1

使用final int pos = viewHolder.getAdapterPosition()不是好主意。因为最终原因pos在您的SnackBar CallBack侦听器中包含您需要的错误索引。您可以使用view.getTag和view.setTag来保持适配器位置的右侧索引。也许这可以帮助你：

@Override 
    public void onSwiped(final RecyclerView.ViewHolder viewHolder, int direction) { 
     // hold position in view item 
     int pos = viewHolder.getAdapterPosition(); 
     view.setTag(pos); 
     communicator.remove(pos); 
     recyclerViewAdapter.notifyItemRemoved(pos); 
     //Snackbar.make(view, R.string.notice_removed, Snackbar.LENGTH_SHORT).show(); 
     Snackbar.make(view, R.string.notice_removed, Snackbar.LENGTH_LONG) 
       .setCallback(new Snackbar.Callback() { 
        @Override 
        public void onDismissed(Snackbar snackbar, int event) { 
         //get position from view item of snackbar that you set it before. 
         int position = (int)snackbar.getView().getTag(); 
         switch (event) { 
          case Snackbar.Callback.DISMISS_EVENT_ACTION: 
           recyclerViewAdapter.notifyItemInserted(position); 
           break; 
          default: 
           communicator.remove(position); 
           break; 
         } 
        } 
       }) 
       .setAction(R.string.action_undo, new View.OnClickListener() { 
        @Override 
        public void onClick(View v) { 
         // do nothing 
        } 
       }) 
       .show(); 

     recyclerViewAdapter.notifyItemRangeChanged(pos, recyclerViewAdapter.getItemCount()); 
    }