notifyItemChanged(int position)更新RecyclerView中的多个项目

Question

我正在使用RecyclerView显示项目列表，并且我需要按位置更新单个项目的状态。我正在更新列表中的项目，然后调用notifyItemChanged(int position)，如下所示:

myList.set(position, newModifiedItem);
notifyItemChanged(position);

项目更新成功，但也随机更新了一些其他项目，每次我上下滚动我的项目列表，这个更新(不同的图标状态)也在其他项目上进行。

我正在更改onBindViewHolder，其中我按位置检查列表项并决定设置不同的状态。

完整适配器代码:

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {
    private List<MyObj> myList;
    public MyAdapter(List<MyObj> list) {
        this.myList = list;
    }
    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.my_item, parent, false);
        return new ViewHolder(view);
    }
    public void onBindViewHolder(final ViewHolder holder, final int position) {
        MyObj myObj = myList.get(position);
        boolean isSpecial = myObj.getMySpecialStatus();
        holder.myItemTitle.setText(myObj.getTitle());
        //decide if item has different icon state
        if (isSpecial) {
            holder.myItemIcon.setImageResource(R.drawable.ic_special);    
        } 
    }
    @Override
    public int getItemCount() {
        return myList.size();
    }

    public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
        public TextView myItemTitle;
        public ImageView myItemIcon;
        public LinearLayout itemClickable;
        //some other views
        public ViewHolder(View itemView) {
            super(itemView);
            myItemTitle = (TextView) itemView.findViewById(R.id.item_title);
            myItemIcon = (ImageView) itemView.findViewById(R.id.item_img);
            itemClickable = (LinearLayout) itemView.findViewById(R.id.item_clickable_zone);
            itemClickable.setOnClickListener(this);
            //some other views
        }
        @Override
        public void onClick(View v) {
            final int position = getAdapterPosition();
            if (position != RecyclerView.NO_POSITION) {
                switch (v.getId()) {
                    case R.id.item_clickable_zone: {
                        //some logic to change status - here just an idea
                        MyObj newModifiedItem = myList.get(position);
                        newModifiedItem.setMySpecialStatus(true);
                        myList.set(position, newModifiedItem);
                        notifyItemChanged(position);
                        break;
                    }
                    //some other views on click
                }
            }
        }
    }
}

Answer 1

问题是在您的onBindViewHolder()中，您没有使用else的if语句。应该是这样的:

public void onBindViewHolder(final ViewHolder holder, final int position) {
        MyObj myObj = myList.get(position);
        boolean isSpecial = myObj.getMySpecialStatus();
        holder.myItemTitle.setText(myObj.getTitle());
        //decide if item has different icon state
        if (isSpecial) {
            holder.myItemIcon.setImageResource(R.drawable.ic_special);    
         } else {
            //here is the trick - set normal state back
            holder.myItemIcon.setImageResource(R.drawable.ic_standard);
         }
    }

Answer 2

试试这个，

MyObj newModifiedItem = myList.get(position); //getting object from the list
newModifiedItem.setMySpecialStatus(true);
notifyItemChanged(position, newModifiedItem);