向下滑动或向上滑动时，在android回收器视图中丢失了所选项目

如何解决向下滑动或向上滑动时，在android回收器视图中丢失了所选项目

我制作了一个回收站视图以显示和选择Instagram帖子，在回收站视图适配器中，我处理了onclick以向用户显示是否选择了项目并处理了选定的帖子的总和...但是当适配器中的insta帖子变为当我滚动页面超过12时，某些选定项目显示为未选定，而某些未选定的帖子看起来就像您选择了它们！谁能帮我 ？ 这是我的适配器：

package com.example.pinstagram.adaptor;

import android.content.Context;
import android.os.Build;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;

import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;

import com.example.pinstagram.R;
import com.example.pinstagram.classes.BuyBasketFlow;
import com.example.pinstagram.classes.InstaPosts;
import com.example.pinstagram.classes.SellingItems;
import com.example.pinstagram.viewHolders.InstaPostsRecyclerViewHolders;
import com.squareup.picasso.Picasso;

import java.util.ArrayList;
import java.util.List;


public class InstaPostsRecyclerViewAdapter extends RecyclerView.Adapter<InstaPostsRecyclerViewHolders> {
    private List<InstaPosts> instaList;
    private List<InstaPosts> selectedPosts;
    LinearLayout linearLayout;
    private Context context;
    TextView numberTextView,eachPostPriceTxt,totalPriceTxt;
    BuyBasketFlow buyBasketFlow;
    SellingItems sellingItems;

    public InstaPostsRecyclerViewAdapter(Context context,List<InstaPosts> itemList,List<InstaPosts> selectedPosts,LinearLayout linearLayout,TextView[] textViews) {
        this.instaList = itemList;
        this.context = context;
        this.selectedPosts = selectedPosts;
        this.linearLayout = linearLayout;
        numberTextView = textViews[0];
        eachPostPriceTxt = textViews [1];
        buyBasketFlow = new BuyBasketFlow();
        sellingItems = new SellingItems();
        selectedPosts.clear();
        for(int i = 0; i < instaList.size();i++){
            instaList.get(i).setSelected(false);
        }
        linearLayout.setVisibility(View.GONE);
    }

    @NonNull
    @Override
    public InstaPostsRecyclerViewHolders onCreateViewHolder(ViewGroup parent,int viewType) {
        View layoutView = LayoutInflater.from(parent.getContext()).inflate(R.layout.isnta_posts_listview,null);
        InstaPostsRecyclerViewHolders crcv = new InstaPostsRecyclerViewHolders(layoutView);
        return crcv;
    }
    @Override
    public void onBindViewHolder(@NonNull final InstaPostsRecyclerViewHolders holder,final int position) {
        holder.cardView.setonClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Log.i("Log3"," item number: " + position + " is clicked");
                instaList.get(position).setSelected(!instaList.get(position).isSelected());
                if(buyBasketFlow.getType().compareto("like")==0) {
                    if (instaList.get(position).isCanBeSelect()) {
                        selectingPhase(holder,position);

                    } else {
                        Toast.makeText(context,R.string.just_select_photo,Toast.LENGTH_SHORT).show();
                        Log.i("Log1",instaList.get(position).getTypename());
                    }
                }else if(buyBasketFlow.getType().compareto("view")==0){
                    if (instaList.get(position).isViewCanBeSelected()) {
                        selectingPhase(holder,R.string.just_select_video,instaList.get(position).getTypename());
                    }

                }else if(buyBasketFlow.getType().compareto("comment")==0){
                    if (instaList.get(position).isViewCanBeSelected()||instaList.get(position).isCanBeSelect()) {
                        selectingPhase(holder,instaList.get(position).getTypename());
                    }
                }
            }
        });

        Picasso.get().load(instaList.get(position).getThumbnail_url()).into(holder.instaimage);
    }
    public List<InstaPosts> getSelectedPosts(){
        return selectedPosts;
    }

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

    private void selectingPhase(InstaPostsRecyclerViewHolders holder,int position){
        if (instaList.get(position).isSelected()) {
            selectedPosts.add(instaList.get(position));
            buyBasketFlow.setPostsArrays(selectedPosts);
            for (InstaPosts selected : selectedPosts) {
                Log.e("Log1",selected.toString());
            }
            holder.radioBtn.setimageDrawable(context.getDrawable(R.drawable.radio_button_checked));
            holder.cardView.setstrokeWidth(10);
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                holder.cardView.setstrokeColor(context.getColor(R.color.colorPrimary));
            }
        } else {
            selectedPosts.remove(instaList.get(position));
            buyBasketFlow.setPostsArrays(selectedPosts);
            for (InstaPosts selected : selectedPosts) {
                Log.e("Log1",selected.toString());
            }
            holder.cardView.setstrokeWidth(0);
            holder.radioBtn.setimageDrawable(context.getDrawable(R.drawable.radio_button_unchecked));
        }
        if (selectedPosts.size() < 1) {
            linearLayout.setVisibility(View.GONE);
            Log.i("Log1","layout must become invisible");

        } else {
            Log.i("Log1","layout must become visible");
            linearLayout.setVisibility(View.VISIBLE);
            sellingItems = buyBasketFlow.getSellingItem();
            numberTextView.setText("" + selectedPosts.size());
            Log.i("Log1","" + Integer.parseInt(sellingItems.getPrice()));
            String text = "قیمت هر پست" + sellingItems.getPrice() + " تومان ";
            String sum = Integer.toString((selectedPosts.size() * Integer.parseInt(sellingItems.getPrice())));
            text = text + "و قیمت مجموع " + sum + " تومان ";
            eachPostPriceTxt.setText(text);
        }
    }
}

解决方法

您每次都需要在onBindViewHolder上设置选定状态。

在onBindViewHolder中：

InstaPosts instaPosts = instaList.get(position);
holder.cardView.setStrokeWidth(instaPosts.isSelected() ? 10 : 0);
holder.radioBtn.setImageDrawable(context.getDrawable(instaPosts.isSelected() ? R.drawable.radio_button_checked : R.drawable.radio_button_unchecked));