android RecyclerView in kotlin example

 android RecyclerView in kotlin example

In this tutorial today learn android RecyclerView in kotlin example. for more information visit google. developer.com

What is the use of RecyclerView in Android?

In Android, RecyclerView provides an ability to implement the horizontal, vertical, and Expandable List. It is mainly used when we have data collections whose elements can change at run time based on user action or any network events.

What is RecyclerView in Android for example?

RecyclerView is a ViewGroup added to the android studio as a successor of the GridView and ListView. It is an improvement on both of them and can be found in the latest v-7 support packages.

follow the example RecyclerView in kotlin android

create a layout file below file name is activity_main.xml:

1.activity_main.xml.

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

   android:id="@+id/rlMain"

   android:layout_width="match_parent"

   android:layout_height="match_parent"

   android:layout_margin="16dp"

   android:orientation="vertical">

<androidx.recyclerview.widget.RecyclerView

   android:id="@+id/recyclerView"

   android:layout_width="match_parent"

   android:layout_height="match_parent" />

</LinearLayout>

create class name is movieList 

2.movieList .kt

import android.os.Bundle

import androidx.appcompat.app.AppCompatActivity

import androidx.recyclerview.widget.DefaultItemAnimator

import androidx.recyclerview.widget.LinearLayoutManager

import androidx.recyclerview.widget.RecyclerView

class MainActivity : AppCompatActivity() {

   private val movieList = ArrayList<MovieModel>()

   private lateinit var moviesAdapter: MoviesAdapter

   override fun onCreate(savedInstanceState: Bundle?) {

      super.onCreate(savedInstanceState)

      setContentView(R.layout.activity_main)

      title = "KotlinApp"

      val recyclerView: RecyclerView = findViewById(R.id.recyclerView)

      moviesAdapter = MoviesAdapter(movieList)

      val layoutManager = LinearLayoutManager(applicationContext)

      recyclerView.layoutManager = layoutManager

      recyclerView.itemAnimator = DefaultItemAnimator()

      recyclerView.adapter = moviesAdapter

      prepareMovieData()

   }

   private fun prepareMovieData() {

      var movie = MovieModel("Mad Max: Fury Road", "Action & Adventure", "2015")

      movieList.add(movie)

      movie = MovieModel("Inside Out", "Animation, Kids & Family", "2015")

      movieList.add(movie)

      movie = MovieModel("Star Wars: Episode VII - The Force Awakens", "Action", "2015")

      movieList.add(movie)

      movie = MovieModel("Shaun the Sheep", "Animation", "2015")

      movieList.add(movie)

      movie = MovieModel("The Martian", "Science Fiction & Fantasy", "2015")

      movieList.add(movie)

      movie = MovieModel("Mission: Impossible Rogue Nation", "Action", "2015")

      movieList.add(movie)

      movie = MovieModel("Up", "Animation", "2009")

      movieList.add(movie)

      movie = MovieModel("Star Trek", "Science Fiction", "2009")

      movieList.add(movie)

      movie = MovieModel("The LEGO MovieModel", "Animation", "2014")

      movieList.add(movie)

      movie = MovieModel("Iron Man", "Action & Adventure", "2008")

      movieList.add(movie)

      movie = MovieModel("Aliens", "Science Fiction", "1986")

      movieList.add(movie)

      movie = MovieModel("Chicken Run", "Animation", "2000")

      movieList.add(movie)

      movie = MovieModel("Back to the Future", "Science Fiction", "1985")

      movieList.add(movie)

      movie = MovieModel("Raiders of the Lost Ark", "Action & Adventure", "1981")

      movieList.add(movie)

      movie = MovieModel("Goldfinger", "Action & Adventure", "1965")

      movieList.add(movie)

      movie = MovieModel("Guardians of the Galaxy", "Science Fiction & Fantasy", "2014")

      movieList.add(movie)

      moviesAdapter.notifyDataSetChanged()

   }

}

create class MovieModel  

3.MovieModel.kt

class MovieModel(title: String?, genre: String?, year: String?) {

   private var title: String

   private var genre: String

   private var year: String

   init {

      this.title = title!!

      this.genre = genre!!

      this.year = year!!

   }

   fun getTitle(): String? {

      return title

   }

   fun setTitle(name: String?) {

      title = name!!

   }

   fun getYear(): String? {

      return year

   }

   fun setYear(year: String?) {

      this.year = year!!

   }

   fun getGenre(): String? {

      return genre

   }

   fun setGenre(genre: String?) {

      this.genre = genre!!

   }

}

create class MoviesAdapter

4.MoviesAdapter.kt

import android.view.LayoutInflater

import android.view.View

import android.view.ViewGroup

import android.widget.TextView

import androidx.annotation.NonNull

import androidx.recyclerview.widget.RecyclerView

internal class MoviesAdapter(private var moviesList: List<MovieModel>) :

RecyclerView.Adapter<MoviesAdapter.MyViewHolder>() {

   internal inner class MyViewHolder(view: View) : RecyclerView.ViewHolder(view) {

      var title: TextView = view.findViewById(R.id.title)

      var year: TextView = view.findViewById(R.id.year)

      var genre: TextView = view.findViewById(R.id.genre)

   }

   @NonNull

   override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyViewHolder {

      val itemView = LayoutInflater.from(parent.context)

      .inflate(R.layout.movie_list, parent, false)

      return MyViewHolder(itemView)

   }

   override fun onBindViewHolder(holder: MyViewHolder, position: Int) {

      val movie = moviesList[position]

      holder.title.text = movie.getTitle()

      holder.genre.text = movie.getGenre()

      holder.year.text = movie.getYear()

   }

   override fun getItemCount(): Int {

      return moviesList.size

   }

}

create layout file name is item_row.xml:

5.item_row.xml:

<?xml version="1.0" encoding="utf-8"?>

<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="100dp"

   android:layout_margin="8dp"

   app:cardBackgroundColor="@android:color/holo_red_dark">

   <RelativeLayout

      android:layout_width="match_parent"

      android:layout_height="match_parent"

      android:padding="8dp">

   <TextView

      android:id="@+id/title"

      android:layout_width="match_parent"

      android:layout_height="wrap_content"

      android:layout_alignParentStart="true"

      android:layout_toStartOf="@+id/year"

      android:textColor="@android:color/white"

      android:textSize="16sp"

      android:textStyle="bold" />

   <TextView

      android:id="@+id/year"

      android:layout_width="wrap_content"

      android:layout_height="wrap_content"

      android:layout_alignParentEnd="true"

      android:textColor="@android:color/white" />

   <TextView

      android:id="@+id/genre"

      android:layout_width="match_parent"

      android:layout_height="wrap_content"

      android:layout_alignParentBottom="true"

      android:textColor="@android:color/white" />

   </RelativeLayout>

</androidx.cardview.widget.CardView>

6.androidMinfeast.xml:

<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.q11">

   <application

      android:allowBackup="true"

      android:icon="@mipmap/ic_launcher"

      android:label="@string/app_name"

      android:roundIcon="@mipmap/ic_launcher_round"

      android:supportsRtl="true"

      android:theme="@style/AppTheme">

      <activity android:name=".MainActivity">

         <intent-filter>

            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />

         </intent-filter>

      </activity>

   </application>

</manifest>