How to build a Video Player in Android

 <?xml version="1.0" encoding="utf-8"?>
 <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity"
    tools:ignore="HardcodedText">

    <VideoView
        android:id="@+id/videoView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_centerVertical="true"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
 </androidx.constraintlayout.widget.ConstraintLayout>

import android.media.MediaPlayer
import android.net.Uri
import android.os.Bundle
import android.view.View
import android.widget.MediaController
import android.widget.VideoView
import androidx.appcompat.app.AppCompatActivity

class MainActivity : AppCompatActivity(),  MediaPlayer.OnCompletionListener {
    @SuppressLint("MissingInflatedId")
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        val videoView = findViewById<View>(R.id.videoView1) as VideoView
        videoView.setVideoURI(Uri.parse("android.resource://" + packageName + "/" + R.raw.demo))
        videoView.setMediaController( MediaController(this));
        videoView.setOnCompletionListener(this@MainActivity);
        videoView.start()
    }

    override fun onCompletion(mp: MediaPlayer?) {
      //onCompletion when video end
    }
}