我一直在使用回收器视图，但不知道为什么在每个分区后都有黑线，尽管我没有任何代码来提升黑线。如果我没有使用任何volley库或picasso库，或者当我使用自己的数组列表时，它在没有任何分隔线的情况下工作得很好。这是XML代码：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/llcontent"
    android:layout_width="match_parent"
    android:layout_height="140dp"
    android:orientation="horizontal"
    android:background="@color/white"
    android:weightSum="6">

    <!--The weight sum property is used to divide the layout into
    different parts and then giving each layout a particular weight
    gives it that amount of space on the screen-->

    <!--Since each parent layout will have a specific weight, we need
    not give any width to those layout-->

    <ImageView
        android:layout_weight="1.5"
        android:id="@+id/imgBookImage"
        android:layout_width="0dp"
        android:layout_height="110dp"
        android:src="@mipmap/ic_launcher"
        android:scaleType="centerCrop"
        android:padding="5dp"/>

    <RelativeLayout
        android:layout_weight="3.3"
        android:layout_width="0dp"
        android:layout_height="match_parent">
        <TextView
            android:id="@+id/txtBookName"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Name of the book"
            android:padding="8dp"
            android:textSize="18sp"
            android:textColor="#000000"/>

        <TextView
            android:id="@+id/txtBookAuthor"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_below="@id/txtBookName"
            android:padding="8dp"
            android:text="Name of the Author"
            android:textSize="15sp" />

        <TextView
            android:id="@+id/txtBookPrice"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_below="@id/txtBookAuthor"
            android:layout_alignParentBottom="true"
            android:padding="8dp"
            android:text="Rs. 299"
            android:textColor="#357a38"
            android:textSize="15sp"
            android:textStyle="bold" />
    </RelativeLayout>

    <!--Many times we see that texts have an image along with them to
    their right or left. This is added with the help of the
    drawableLeft (or drawableRight and so on) attribute-->

    <TextView
        android:id="@+id/txtBookRating"
        android:layout_weight="1.2"
        android:layout_width="0dp"
        android:padding="4dp"
        android:layout_height="wrap_content"
        android:drawableLeft="@drawable/ic_ratings"
        android:textColor="#ffca28"
        android:text="4.5"
        android:drawablePadding="4dp"
        android:textSize="15sp"
        android:textStyle="bold">

    </TextView>

</LinearLayout>

这与Kotlin的代码相同：

package com.example.new_app.fragment

import android.app.Activity
import android.app.AlertDialog
import android.app.Dialog
import android.content.ContentValues.TAG
import android.content.Context
import android.os.Bundle
import android.util.Log
import androidx.fragment.app.Fragment
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.Toast
import androidx.recyclerview.widget.DividerItemDecoration
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.recyclerview.widget.RecyclerView
import com.android.volley.Request
import com.android.volley.Response
import com.android.volley.toolbox.JsonObjectRequest
import com.android.volley.toolbox.Volley
import com.example.new_app.R
import com.example.new_app.adapter.Dashboard_Recycler_Adapter
import com.example.new_app.model.book
import isOnline
import java.util.stream.DoubleStream.builder
import java.util.stream.Stream.builder
import android.content.Intent
import android.provider.Settings
import androidx.core.app.ActivityCompat
import android.R.string.no



class dashboard_fragment : Fragment() {
    lateinit var recyclerView: RecyclerView
    lateinit var layoutManager: RecyclerView.LayoutManager
    lateinit var adapter: Dashboard_Recycler_Adapter
     var bookInfoList: ArrayList<book> = ArrayList()
    val TAGG = "onCreateView"
    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
//        val bookInfoList = arrayListOf<book>(
//           book("1", "yname", "hfer", "200", "5", R.drawable.anna_kare)
//        )

        val view =  inflater.inflate(R.layout.fragment_dashboard_fragment, container, false)
        recyclerView = view.findViewById(R.id.rvdashboard)

        layoutManager = LinearLayoutManager(activity)
        adapter = Dashboard_Recycler_Adapter(activity as Context, bookInfoList)

        recyclerView.adapter = adapter
        recyclerView.layoutManager = layoutManager

        val a = ((isOnline(activity as Context))).toString()

        if(!isOnline(activity as Context)) {
            val dialog = AlertDialog.Builder(activity as Context)
            dialog.setTitle("Error")
            dialog.setMessage("Network is not working")
            dialog.setPositiveButton("Open settings"){
                text, listener->
                val intent = Intent(Settings.ACTION_WIRELESS_SETTINGS)
                startActivity(intent)
            }
            dialog.setNegativeButton("Cancel"){
                    text, listener->
                    ActivityCompat.finishAffinity(activity as Activity)
            }
            dialog.create()
            dialog.show()
            return view
        }
        val queue = Volley.newRequestQueue(activity as Context)
        val url = "http://13.235.250.119/v1/book/fetch_books/"

        val jsonObjectRequest = object: JsonObjectRequest(Request.Method.GET,
        url, null,
            Response.Listener {
                val success = it.getBoolean("success")
                if(success)
                {
                    val data = it.getJSONArray("data")
                    for(i in 0 until data.length())
                    {
                        val bookjsonobj = data.getJSONObject(i)
                        val booklist = book(
                            bookjsonobj.getString("book_id"),
                            bookjsonobj.getString("name"),
                            bookjsonobj.getString("author"),
                            bookjsonobj.getString("rating"),
                            bookjsonobj.getString("price"),
                            bookjsonobj.getString("image")
                        )
                        bookInfoList.add(booklist)

                        layoutManager = LinearLayoutManager(activity)
                        adapter = Dashboard_Recycler_Adapter(activity as Context, bookInfoList)

                        recyclerView.adapter = adapter
                        recyclerView.layoutManager = layoutManager

                        recyclerView.addItemDecoration(
                            DividerItemDecoration(
                                recyclerView.context,
                                (layoutManager as LinearLayoutManager).orientation
                            )
                        )
                    }

                }

            }, Response.ErrorListener {
                    print("Not proceccess")
            })

        {
            override fun getHeaders(): MutableMap<String, String> {
                val headers = hashMapOf<String, String>()
                headers["Content-type"] = "application/json"
                headers["token"] = ""
                return headers
            }
        }
        queue.add(jsonObjectRequest)
        return view
    }

}