Android RecyclerView & ListView — Adapter, ViewHolder, CardView

Lists Overview

Android apps constantly show scrollable lists — contacts, messages, products, feeds. Two main widgets handle this: ListView (legacy) and RecyclerView (modern, recommended).

Data List (List<Item>) ↓ Adapter (binds data → views) ↓ ListView / RecyclerView (displays rows) ↓ ViewHolder (caches row view references)

Feature	ListView	RecyclerView
View recycling	Basic	Advanced, flexible
Layout managers	Vertical only	Linear, Grid, Staggered
Animations	Manual	Built-in item animations
Performance	OK for simple lists	Optimized for large datasets
Recommendation	Legacy / learning only	Use for all new projects

1ListView Basics

ListView displays a vertically scrollable list of items. It requires an Adapter to supply data and inflate row layouts.

Simple ListView with ArrayAdapter

XML — activity_main.xml<ListView
    android:id="@+id/listView"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:divider="@android:color/darker_gray"
    android:dividerHeight="1dp"
    android:padding="8dp" />

Kotlin — Simple ArrayAdapterclass MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val fruits = listOf("Apple", "Banana", "Cherry", "Date", "Elderberry")
        val adapter = ArrayAdapter(
            this,
            android.R.layout.simple_list_item_1,
            fruits
        )

        findViewById<ListView>(R.id.listView).adapter = adapter
    }
}

Handle item clicks

Kotlin — ListView item clickfindViewById<ListView>(R.id.listView).setOnItemClickListener { _, _, position, _ ->
    val selected = fruits[position]
    Toast.makeText(this, "You picked: $selected", Toast.LENGTH_SHORT).show()
}

ListView limitations

Only vertical scrolling — no grid or staggered layouts out of the box
Recycling is less efficient than RecyclerView for large lists
Harder to add item animations and complex row layouts
Google recommends RecyclerView for all new development

2Custom Adapter

A custom adapter gives full control over row layout and data binding. Extend BaseAdapter for ListView or RecyclerView.Adapter for RecyclerView.

Data model

Kotlin — Contact.ktdata class Contact(
    val id: Int,
    val name: String,
    val email: String,
    val avatarRes: Int
)

Row layout

XML — item_contact.xml<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    android:padding="12dp"
    android:gravity="center_vertical">

    <ImageView
        android:id="@+id/ivAvatar"
        android:layout_width="48dp"
        android:layout_height="48dp"
        android:src="@drawable/ic_avatar"
        android:contentDescription="@string/avatar" />

    <LinearLayout
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:layout_marginStart="12dp"
        android:orientation="vertical">

        <TextView
            android:id="@+id/tvName"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textSize="16sp"
            android:textStyle="bold" />

        <TextView
            android:id="@+id/tvEmail"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textSize="14sp"
            android:textColor="#666666" />

    </LinearLayout>

</LinearLayout>

Custom BaseAdapter for ListView

Kotlin — ContactListAdapter.ktclass ContactListAdapter(
    private val context: Context,
    private val contacts: List<Contact>
) : BaseAdapter() {

    override fun getCount(): Int = contacts.size
    override fun getItem(position: Int): Contact = contacts[position]
    override fun getItemId(position: Int): Long = contacts[position].id.toLong()

    override fun getView(position: Int, convertView: View?, parent: ViewGroup?): View {
        val view = convertView ?: LayoutInflater.from(context)
            .inflate(R.layout.item_contact, parent, false)

        val contact = contacts[position]
        view.findViewById<TextView>(R.id.tvName).text = contact.name
        view.findViewById<TextView>(R.id.tvEmail).text = contact.email
        view.findViewById<ImageView>(R.id.ivAvatar).setImageResource(contact.avatarRes)

        return view
    }
}

3RecyclerView Setup

RecyclerView is the modern list widget. It separates layout management (LinearLayoutManager, GridLayoutManager) from data binding (Adapter).

Gradle dependency

Kotlin — app/build.gradle.ktsdependencies {
    implementation("androidx.recyclerview:recyclerview:1.3.2")
    implementation("androidx.cardview:cardview:1.0.0")
}

Layout XML

XML — activity_main.xml<androidx.recyclerview.widget.RecyclerView
    android:id="@+id/recyclerView"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:clipToPadding="false"
    android:padding="8dp"
    android:scrollbars="vertical" />

Setup in Activity

Kotlin — MainActivity.ktclass MainActivity : AppCompatActivity() {

    private lateinit var recyclerView: RecyclerView
    private lateinit var adapter: ContactAdapter

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        recyclerView = findViewById(R.id.recyclerView)
        recyclerView.layoutManager = LinearLayoutManager(this)
        recyclerView.setHasFixedSize(true)

        val contacts = listOf(
            Contact(1, "Nikhil", "nikhil@example.com", R.drawable.avatar1),
            Contact(2, "Priya", "priya@example.com", R.drawable.avatar2),
            Contact(3, "Rahul", "rahul@example.com", R.drawable.avatar3)
        )

        adapter = ContactAdapter(contacts) { contact ->
            Toast.makeText(this, "Clicked: ${contact.name}", Toast.LENGTH_SHORT).show()
        }
        recyclerView.adapter = adapter
    }
}

Layout managers

LayoutManager	Layout	Code
`LinearLayoutManager`	Vertical or horizontal list	`LinearLayoutManager(context)`
`GridLayoutManager`	Grid of items	`GridLayoutManager(context, 2)` (2 columns)
`StaggeredGridLayoutManager`	Pinterest-style masonry	`StaggeredGridLayoutManager(2, VERTICAL)`

4ViewHolder Pattern

The ViewHolder pattern caches references to row views so findViewById is called once per row creation, not on every scroll. RecyclerView requires this pattern in its Adapter.

Why it matters: Without ViewHolder, scrolling a 1000-item list would call findViewById thousands of times, causing jank and battery drain.

ContactAdapter with ViewHolder

Kotlin — ContactAdapter.ktclass ContactAdapter(
    private val contacts: List<Contact>,
    private val onItemClick: (Contact) -> Unit
) : RecyclerView.Adapter<ContactAdapter.ContactViewHolder>() {

    inner class ContactViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        val ivAvatar: ImageView = itemView.findViewById(R.id.ivAvatar)
        val tvName: TextView = itemView.findViewById(R.id.tvName)
        val tvEmail: TextView = itemView.findViewById(R.id.tvEmail)

        fun bind(contact: Contact) {
            ivAvatar.setImageResource(contact.avatarRes)
            tvName.text = contact.name
            tvEmail.text = contact.email
            itemView.setOnClickListener { onItemClick(contact) }
        }
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ContactViewHolder {
        val view = LayoutInflater.from(parent.context)
            .inflate(R.layout.item_contact, parent, false)
        return ContactViewHolder(view)
    }

    override fun onBindViewHolder(holder: ContactViewHolder, position: Int) {
        holder.bind(contacts[position])
    }

    override fun getItemCount(): Int = contacts.size
}

Adapter lifecycle methods

onCreateViewHolder() → Inflate row layout, create ViewHolder (rare) ↓ onBindViewHolder() → Bind data to ViewHolder views (every visible row) ↓ [User scrolls] ↓ View recycled → Same ViewHolder reused with new data

View Binding in ViewHolder (recommended)

Kotlin — ViewHolder with View Bindinginner class ContactViewHolder(
    private val binding: ItemContactBinding
) : RecyclerView.ViewHolder(binding.root) {

    fun bind(contact: Contact) {
        binding.ivAvatar.setImageResource(contact.avatarRes)
        binding.tvName.text = contact.name
        binding.tvEmail.text = contact.email
        binding.root.setOnClickListener { onItemClick(contact) }
    }
}

override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ContactViewHolder {
    val binding = ItemContactBinding.inflate(
        LayoutInflater.from(parent.context), parent, false
    )
    return ContactViewHolder(binding)
}

5CardView

CardView wraps list items in a Material card with rounded corners, elevation shadow, and padding — ideal for feeds, product lists, and news cards.

Card item layout

XML — item_product_card.xml<androidx.cardview.widget.CardView
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_margin="8dp"
    app:cardCornerRadius="12dp"
    app:cardElevation="4dp"
    app:cardUseCompatPadding="true">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <ImageView
            android:id="@+id/ivProduct"
            android:layout_width="match_parent"
            android:layout_height="160dp"
            android:scaleType="centerCrop"
            android:contentDescription="@string/product_image" />

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            android:padding="12dp">

            <TextView
                android:id="@+id/tvTitle"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:textSize="16sp"
                android:textStyle="bold" />

            <TextView
                android:id="@+id/tvPrice"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginTop="4dp"
                android:textColor="?attr/colorPrimary"
                android:textSize="18sp"
                android:textStyle="bold" />

        </LinearLayout>
    </LinearLayout>

</androidx.cardview.widget.CardView>

Product model and adapter

Kotlin — Product.kt + ProductAdapter.ktdata class Product(val id: Int, val title: String, val price: Double, val imageRes: Int)

class ProductAdapter(
    private val products: List<Product>,
    private val onItemClick: (Product) -> Unit
) : RecyclerView.Adapter<ProductAdapter.ProductViewHolder>() {

    inner class ProductViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        private val ivProduct: ImageView = itemView.findViewById(R.id.ivProduct)
        private val tvTitle: TextView = itemView.findViewById(R.id.tvTitle)
        private val tvPrice: TextView = itemView.findViewById(R.id.tvPrice)

        fun bind(product: Product) {
            ivProduct.setImageResource(product.imageRes)
            tvTitle.text = product.title
            tvPrice.text = "₹${product.price}"
            itemView.setOnClickListener { onItemClick(product) }
        }
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int) =
        ProductViewHolder(
            LayoutInflater.from(parent.context)
                .inflate(R.layout.item_product_card, parent, false)
        )

    override fun onBindViewHolder(holder: ProductViewHolder, position: Int) =
        holder.bind(products[position])

    override fun getItemCount() = products.size
}

Grid layout with CardView

Kotlin — 2-column product gridrecyclerView.layoutManager = GridLayoutManager(this, 2)
recyclerView.adapter = ProductAdapter(productList) { product ->
    startActivity(Intent(this, ProductDetailActivity::class.java).apply {
        putExtra("product_id", product.id)
    })
}

6Dynamic Lists

Dynamic lists change at runtime — add, remove, update, or filter items. Use notifyDataSetChanged() for simple updates, or DiffUtil for efficient animated diffs.

Mutable list with notify methods

Kotlin — Dynamic ContactAdapterclass ContactAdapter(
    private val contacts: MutableList<Contact>,
    private val onItemClick: (Contact) -> Unit
) : RecyclerView.Adapter<ContactAdapter.ContactViewHolder>() {

    // ... ViewHolder code same as before ...

    fun addContact(contact: Contact) {
        contacts.add(contact)
        notifyItemInserted(contacts.size - 1)
    }

    fun removeContact(position: Int) {
        contacts.removeAt(position)
        notifyItemRemoved(position)
    }

    fun updateContact(position: Int, contact: Contact) {
        contacts[position] = contact
        notifyItemChanged(position)
    }

    fun clearAll() {
        val size = contacts.size
        contacts.clear()
        notifyItemRangeRemoved(0, size)
    }
}

Swipe to delete with ItemTouchHelper

Kotlin — Swipe-to-deleteval swipeHandler = object : ItemTouchHelper.SimpleCallback(0, ItemTouchHelper.LEFT or ItemTouchHelper.RIGHT) {
    override fun onMove(
        recyclerView: RecyclerView,
        viewHolder: RecyclerView.ViewHolder,
        target: RecyclerView.ViewHolder
    ): Boolean = false

    override fun onSwiped(viewHolder: RecyclerView.ViewHolder, direction: Int) {
        adapter.removeContact(viewHolder.adapterPosition)
        Snackbar.make(recyclerView, "Contact deleted", Snackbar.LENGTH_SHORT)
            .setAction("Undo") {
                // Re-add deleted item if needed
            }.show()
    }
}
ItemTouchHelper(swipeHandler).attachToRecyclerView(recyclerView)

DiffUtil for efficient updates

Kotlin — DiffUtil with ListAdapterclass ContactDiffCallback : DiffUtil.ItemCallback<Contact>() {
    override fun areItemsTheSame(old: Contact, new: Contact) = old.id == new.id
    override fun areContentsTheSame(old: Contact, new: Contact) = old == new
}

class ContactListAdapter : ListAdapter<Contact, ContactListAdapter.ViewHolder>(ContactDiffCallback()) {
    // onCreateViewHolder / onBindViewHolder same as before
}

// Submit new list — DiffUtil calculates minimal changes automatically
adapter.submitList(newContactList)

Load data from API (Coroutine pattern)

Kotlin — Fetch and update listlifecycleScope.launch {
    try {
        progressBar.visibility = View.VISIBLE
        val response = apiService.getContacts()
        adapter.submitList(response.data)
    } catch (e: Exception) {
        Toast.makeText(this@MainActivity, "Failed to load", Toast.LENGTH_SHORT).show()
    } finally {
        progressBar.visibility = View.GONE
    }
}

7Hands-On Exercises

1

Create a simple ListView with 10 fruit names using ArrayAdapter. Show a Toast with the selected item on click.

2

Build a custom adapter for a contact list with avatar, name, and email in each row.

3

Convert the contact list to RecyclerView with LinearLayoutManager and implement the ViewHolder pattern.

4

Redesign list items using CardView with rounded corners and elevation. Display a product catalog (title, price, image).

5

Switch to GridLayoutManager with 2 columns for the product cards.

6

Add a FAB button that inserts a new contact at the top. Use notifyItemInserted(0) for smooth animation.

7

Implement swipe-to-delete with ItemTouchHelper and an Undo Snackbar.

8

Bonus: Refactor to ListAdapter with DiffUtil. Load contacts from a JSON file or REST API and call submitList().

RecyclerView & ListView MCQ Practice

10 Basic MCQs 10 Advanced MCQs

10 Basic RecyclerView & ListView MCQs

1

RecyclerView replaces ListView because?

ABetter recycling and flexible layout managers

BSmaller APK always

CNo adapter needed

DDeprecated XML

Explanation: RecyclerView decouples layout, animation, and ViewHolder pattern.

2

ViewHolder pattern purpose?

ACache view references per row

BHold Activity instance

CStore APK

DReplace manifest

Explanation: ViewHolder avoids repeated findViewById in scroll.

3

LayoutManager for vertical list?

ALinearLayoutManager

BGridLayout only

CConstraintLayout

DFrameLayoutManager

Explanation: LinearLayoutManager(VERTICAL) is default list layout.

4

Adapter methods include?

AonCreateViewHolder, onBindViewHolder, getItemCount

BonCreate only

ConResume

DsetContentView

Explanation: RecyclerView.Adapter core trio binds data to views.

5

ListView needs adapter like?

AArrayAdapter or BaseAdapter

BNavController

CService

DFragmentManager

Explanation: Adapters map data to row views in ListView.

6

ItemDecoration in RecyclerView?

AAdds dividers/offsets between items

BDeletes items

CSigns APK

DStarts Activity

Explanation: DividerItemDecoration draws separators.

7

notifyDataSetChanged downside?

AInefficient full refresh without diff

BIllegal method

COnly for ListView

DCrashes always

Explanation: Prefer ListAdapter + DiffUtil for granular updates.

8

GridLayoutManager spans?

AMulti-column grid

BOnly one column always

CHorizontal only banned

DServices

Explanation: spanCount sets columns in grid mode.

9

CardView provides?

ARounded corners and elevation shadow

BSQL database

CGPS

DNative HAL

Explanation: Material card container for list item rows.

10

setHasFixedSize(true) when?

ARecyclerView size doesn't depend on adapter item count

BNever

CAlways illegal

DListView only

Explanation: Optimization when RV dimensions are fixed despite data changes.

10 Advanced RecyclerView & ListView MCQs

11

DiffUtil calculates?

AMinimal adapter updates between old/new lists

BDex diff

CGradle diff

DManifest merge

Explanation: DiffUtil dispatches notifyItem* for changed positions only.

12

ListAdapter requires?

ADiffUtil.ItemCallback for compare

BNo ViewHolder

CListView parent

DService binding

Explanation: ListAdapter + DiffUtil.ItemCallback simplify async list updates.

13

RecycledViewPool shares?

AViewHolders across RecyclerViews

BAPK cache

CIntent extras

DPermissions

Explanation: Shared pool improves nested horizontal lists performance.

14

ItemTouchHelper enables?

ASwipe to dismiss and drag reorder

BNetwork refresh

CCamera preview

DGradle sync

Explanation: Attach ItemTouchHelper.Callback for interactive list gestures.

15

ConcatAdapter?

ACombines multiple adapters sequentially

BMerges APKs

CSQL JOIN

DFragment merge

Explanation: Shows headers, sections, footers from separate adapters.

16

Stable IDs in RecyclerView?

AsetHasStableIds helps animation consistency

BRequired always

CBanned

DListView only

Explanation: Stable item IDs improve change animations when enabled.

17

Nested RecyclerView performance tip?

AShare RecycledViewPool, avoid wrap_content height

BDisable scrolling

CUse ListView inside ListView

DRemove ViewHolder

Explanation: Nested RV with same orientation needs careful sizing and pool sharing.

18

Pull to refresh typically with?

ASwipeRefreshLayout wrapping RecyclerView

BProgressBar in manifest

CADB

DIntent filter

Explanation: SwipeRefreshLayout triggers reload onPull.

19

Paging 3 library integrates with?

ARecyclerView via PagingDataAdapter

BListView only

CServices

DHAL

Explanation: Paging loads pages incrementally from network/DB.

20

Empty view pattern for RecyclerView?

AObserve adapter item count toggle empty TextView visibility

BBuilt-in emptyView attribute

CAutomatic always

DGradle property

Explanation: No native emptyView — observe data and show placeholder layout.

Click an option to select, then check answers.

RecyclerView & ListView Interview Q&A

15 topic-focused questions for interviews and revision.

1Why prefer RecyclerView over ListView?easy

Answer: Flexible LayoutManagers, item animations, predictable ViewHolder, ItemDecoration, better performance for complex lists.

2Explain ViewHolder pattern.easy

Answer: onCreateViewHolder inflates row layout into ViewHolder; onBindViewHolder sets data using cached view references.

3Steps to setup RecyclerView.easy

Answer: Add dependency, XML RecyclerView, create Adapter + ViewHolder, set layoutManager and adapter on RecyclerView.

4Difference between ListView and RecyclerView scrolling.medium

Answer: Both scroll; RecyclerView recycles more efficiently and supports horizontal/grid/staggered layouts.

5What is DiffUtil?medium

Answer: Compares old and new lists computing insert/remove/move/change operations for efficient adapter notifications.

6How to add dividers between items?easy

Answer: Add DividerItemDecoration with orientation to RecyclerView.

7CardView in list item layout.easy

Answer: Wrap row content in CardView with margin and cardElevation for Material list appearance.

8Handle item click in RecyclerView.medium

Answer: Set click listener in onBindViewHolder on itemView or use separate interface callback with position.

9Swipe to delete implementation overview.hard

Answer: ItemTouchHelper.SimpleCallback with swipe flags; onSwiped remove item and notify adapter.

10Dynamic list: add item at runtime.medium

Answer: Mutable list in ViewModel, add element, submitList (ListAdapter) or notifyItemInserted.

11Grid vs linear list choice.easy

Answer: Linear for standard feeds; GridLayoutManager for galleries/product grids with spanCount.

12Common mistake: not calling notify after data change.easy

Answer: UI won't update — use appropriate notify* or ListAdapter.submitList.

13RecyclerView wrap_content height issue in ScrollView.hard

Answer: Avoid nesting vertical RV in ScrollView with wrap_content — use NestedScrollView + single adapter or pagination.

14Load images in list with Coil.medium

Answer: imageView.load(url) in onBindViewHolder; Coil cancels previous request on rebind automatically.

15Testing RecyclerView items.hard

Answer: Espresso onView(withId(R.id.recycler)).perform(actionOnItemAtPosition(...)) or IdlingResource.

RecyclerView & ListView

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