Recycleviewer item got doubled when returning back from fragment-CodePudding

The problem here is when I'm returning from my support fragment to home fragment back every time my items in the recycle viewer got doubled. Each time i am shifting fragment to fragment my recycle viewer item in the homefragment got doubled. But when, I reopen the app its all got corrected but when i click on another fragment and come back the item in recycle viewer in home fragment got doubled. Kindly help me


// **HomeFragment.kt**



package com.service.bookitapp
import android.os.Bundle
import androidx.fragment.app.Fragment
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.recyclerview.widget.GridLayoutManager
import androidx.recyclerview.widget.RecyclerView
import kotlinx.android.synthetic.main.fragment_home.*


private const val ARG_PARAM1 = "param1"
private const val ARG_PARAM2 = "param2"


class HomeFragment : Fragment() {

    private var param1: String? = null
    private var param2: String? = null
    private val arrCategory = ArrayList<CategoryModel>()

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        // Inflate the layout for this fragment
        val view = inflater.inflate(R.layout.fragment_home, container, false)
        return view
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)

        val recyclerView =view.findViewById<RecyclerView>(R.id.recyclerCategory)

        arrCategory.add(CategoryModel(R.drawable.electrician,"Electrician"))
        arrCategory.add(CategoryModel(R.drawable.plumber,"Plumber"))
        arrCategory.add(CategoryModel(R.drawable.acservice,"AC Service"))
        arrCategory.add(CategoryModel(R.drawable.carpentry,"Carpentry"))
        arrCategory.add(CategoryModel(R.drawable.drop,"Pick up & Drop"))
        arrCategory.add(CategoryModel(R.drawable.painting,"Painting"))
        arrCategory.add(CategoryModel(R.drawable.waterfilter,"Water Filter Repair"))
        arrCategory.add(CategoryModel(R.drawable.packer,"Pack and Move"))

        recyclerView.layoutManager = GridLayoutManager(context,3)
        val recyclerAdapter = context?.let { RecycleCategoryAdapter(it,arrCategory) }
        recyclerView.adapter = recyclerAdapter
    }

}














// **fragment_home.xml**


<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#FAF9F6"
    android:padding="5dp"
    android:orientation="vertical"
    tools:context=".HomeFragment">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        tools:ignore="UselessParent">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/welcome_user"
            android:textColor="@color/teal_200"
            android:textSize="28sp"
            android:padding="8dp"
            android:textStyle="bold"
            tools:ignore="RelativeOverlap" />

        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="50dp"
            android:layout_alignParentEnd="true"
            android:src="@drawable/profile"
            android:padding="4dp"
            android:contentDescription="@string/app_name" />

    </RelativeLayout>


    <RelativeLayout
        android:layout_marginTop="5dp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="4dp">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/catg"
            android:textStyle="bold"
            android:textColor="#6E16e8"
            android:layout_alignParentStart="true"
            android:textSize="22sp"/>


    </RelativeLayout>

    <androidx.recyclerview.widget.RecyclerView
        android:layout_marginTop="5dp"
        android:layout_width="match_parent"
        android:layout_height="370dp"



        android:id="@ id/recyclerCategory">


    </androidx.recyclerview.widget.RecyclerView>


    <LinearLayout
        android:layout_marginTop="10dp"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@string/offers"
            android:textStyle="bold"
            android:layout_marginBottom="5dp"
            android:textColor="#6E16e8"
            android:textSize="22sp"/>

        <HorizontalScrollView
            android:layout_margin="8dp"
            android:layout_width="350dp"
            android:layout_height="200dp"
            tools:ignore="UselessParent">

            <LinearLayout
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:orientation="horizontal">

                <ImageView
                    android:layout_width="350dp"
                    android:layout_height="wrap_content"
                    android:src="@drawable/plumbingservice"
                    android:contentDescription="@string/elect" />

                <ImageView
                    android:layout_width="350dp"
                    android:layout_height="wrap_content"
                    android:contentDescription="@string/elect"
                    android:src="@drawable/cleanview" />

                <ImageView
                    android:layout_width="360dp"
                    android:layout_height="wrap_content"
                    android:contentDescription="@string/elect"
                    android:src="@drawable/elecview" />

            </LinearLayout>
        </HorizontalScrollView>

    </LinearLayout>

</LinearLayout>

The followig are the images

CodePudding user response：

first solution, before add first item in list, call clear

arrCategory.clear()

second solution, populate your list in onCreate method of your fragment

CodePudding user response：

Have you tried moving this

private val arrCategory = ArrayList<CategoryModel>(),

locally inside onViewCreated() ?

like this

override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
    super.onViewCreated(view, savedInstanceState)

    val recyclerView =view.findViewById<RecyclerView>(R.id.recyclerCategory)

    val arrCategory = ArrayList<CategoryModel>() // <-- like this?
    
    arrCategory.add(CategoryModel(R.drawable.electrician,"Electrician")            
    ...
    ...
    ...

or you can simply initialize the list like this, removing all of it out of the onCreate()

private val arrCategory = arrayListOf<CategoryModel>(
         CategoryModel(R.drawable.electrician,"Electrician"),
         CategoryModel(R.drawable.plumber,"Plumber"),
         CategoryModel(R.drawable.acservice,"AC Service"),
         CategoryModel(R.drawable.carpentry,"Carpentry"),
         CategoryModel(R.drawable.drop,"Pick up & Drop"),
         CategoryModel(R.drawable.painting,"Painting"),
         CategoryModel(R.drawable.waterfilter,"Water Filter Repair"),
         CategoryModel(R.drawable.packer,"Pack and Move")
)

override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
    super.onViewCreated(view, savedInstanceState)

    val recyclerView =view.findViewById<RecyclerView>(R.id.recyclerCategory)

    recyclerView.layoutManager = GridLayoutManager(context,3)
    val recyclerAdapter = context?.let { RecycleCategoryAdapter(it,arrCategory) }
    recyclerView.adapter = recyclerAdapter
}