我在我的 recyclerview 中有两个按钮，用于增加(+)和减少(-)数量值，就像购物车应用程序一样，同时增加第 0 个项目的项目值我的下一个项目，即第 1 个增加第 0 个项目的 previuos 值意味着如果我的第 0 项的值为 4，对于第 1 项，如果我将它递增 1，那么它将直接取 5，而不是从 0 开始。

public class TeaListAdapter extends RecyclerView.Adapter<TeaListAdapter.MyViewHolder> {
    private  int num=0;

    private List<TeaListPOJO> teaItemList;

    public class MyViewHolder extends RecyclerView.ViewHolder {
        public TextView tvitemName, tvitemRate,number;
        public ImageView ivItemImg;
        public Button btnIncrease,btnDecrease;
        RecyclerView.ViewHolder holder;


        public MyViewHolder(View view) {
            super(view);
            tvitemName = (TextView) view.findViewById(R.id.txt_item_name);
            tvitemRate = (TextView) view.findViewById(R.id.txt_item_price);
            ivItemImg= (ImageView) view.findViewById (R.id.iv_item);
            number=(TextView) view.findViewById (R.id.integer_number);
            btnIncrease =view.findViewById(R.id.btn_increase);
            btnDecrease = view.findViewById(R.id.btn_decrease);

        }
    }


    public TeaListAdapter(List<TeaListPOJO> teaItemList) {

        this.teaItemList = teaItemList;
    }

    @Override
    public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View itemView = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.rv_placeorder_items, parent, false);

        return new MyViewHolder (itemView);
    }

    @Override
    public void onBindViewHolder(final MyViewHolder holder, final int position) {

        final TeaListPOJO tealist = teaItemList.get(position);
        holder.tvitemName.setText(tealist.getItemName ());
        holder.tvitemRate.setText(AppConstants.INDIAN_RUPEE_SIGN.concat (tealist.getItemRate ()));
       // holder.number.setText (tealist.getQty ());
        holder.btnIncrease.setOnClickListener (new View.OnClickListener () {
            @Override
            public void onClick(View view) {
                num++;
                holder.number.setText (String.valueOf (num));
                notifyDataSetChanged();
            }
        });
        holder.btnDecrease.setOnClickListener (new View.OnClickListener () {
            @Override
            public void onClick(View view) {
                if(num>0)
                num--;
                holder.number.setText (String.valueOf (num));

            }
        });

        byte[] decodedString = new byte[0];
        try {
            decodedString = Base64.decode(tealist.getImageStr(), Base64.DEFAULT);
            // tenantModelPOJO.setLogo(decodedString);
            Bitmap bmp = BitmapFactory.decodeByteArray(decodedString, 0, decodedString.length);
            holder.ivItemImg.setImageBitmap(Bitmap.createScaledBitmap(bmp,60,
                    60, false));
        } catch (Exception e) {
            e.printStackTrace();
        }

    }


    @Override
    public int getItemCount() {

        return teaItemList.size();
    }
}

最佳答案

您的问题是只为所有 View 声明一个变量，您应该从TextView 中获取值然后修改，然后将其设置回TextView 试试这段代码

 holder.btnIncrease.setOnClickListener (new View.OnClickListener () {
            @Override
            public void onClick(View view) {
               int val = 0; 
                try{

                val = Integer.parseInt(holder.number.getText().toString());  
                }catch(Exception e) {
                val = 0; 
                }
                holder.number.setText (String.valueOf (val++));

            }
        });
        holder.btnDecrease.setOnClickListener (new View.OnClickListener () {
            @Override
            public void onClick(View view) {


                int val = 0; 
                try{

                val = Integer.parseInt(holder.number.getText().toString());  
                }catch(Exception e) {
                val = 0; 
                }
                if(val>0) val--;
                holder.number.setText (String.valueOf (val));

            }
        });

关于java - RecyclerView 增加(+)和减少(-)按钮不能为每个项目正常工作，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/56945813/