How to Create an Alert Dialog Box 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:id="@+id/idRLContainer"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/txtTitle"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="10dp"
        android:layout_marginTop="28dp"
        android:text="Candidroot solutions"
        android:textAlignment="center"
        android:textSize="18sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.842"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/btndialog"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="292dp"
        android:layout_marginStart="30dp"
        android:layout_marginEnd="30dp"
        android:text="click to show alert dialog"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/txtTitle" />

 </androidx.constraintlayout.widget.ConstraintLayout>

 import android.content.DialogInterface
 import android.os.Bundle
 import android.widget.Button
 import androidx.appcompat.app.AppCompatActivity

 class MainActivityone : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main_activityone)
        val btndialog = findViewById<Button>(R.id.btndialog)
        btndialog.setOnClickListener {
            showdialogdemo()
        }

    }

    @Deprecated("This method has been deprecated in favor of using the\n      {@link OnBackPressedDispatcher} via {@link #getOnBackPressedDispatcher()}.\n      The OnBackPressedDispatcher controls how back button events are dispatched\n      to one or more {@link OnBackPressedCallback} objects.")
    fun showdialogdemo() {

        //Create object of alertdialog builder
        val builder: android.app.AlertDialog.Builder =
            android.app.AlertDialog.Builder(this@MainActivityone)

        //created object set message
        builder.setMessage("Do you want to Logout ?")

        //created object set title
        builder.setTitle("Alert !")

        //created object set cancelable
        builder.setCancelable(false)

        //set yes button in alert dialog
        builder.setPositiveButton(
            "Yes"
        ) { dialog: DialogInterface?, which: Int ->
            finish()
        }

        //set no button in alert dialog
        builder.setNegativeButton(
            "No"
        ) { dialog: DialogInterface, which: Int ->
            dialog.cancel()
        }

        val alertDialog: android.app.AlertDialog? = builder.create()

        alertDialog?.show()
    }
 }