[Kotlin] AlertDialog

activity_main.xml

<?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:layout_gravity="center"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/btnShow"
        android:textAllCaps="false"
        android:text="Alert"
        android:textSize="30dp"
        android:textStyle="bold"
        android:background="#FFBBBB"
        android:layout_width="200dp"
        android:layout_height="100dp"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"/>

</androidx.constraintlayout.widget.ConstraintLayout>

activity_main.xml

 

 

 

 

 

MainActivity.kt

package com.jwsoft.kotlinproject

import android.content.DialogInterface
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.widget.Toast
import androidx.appcompat.app.AlertDialog
import kotlinx.android.synthetic.main.activity_main.*

class MainActivity : AppCompatActivity() {

    lateinit var alertDialog: AlertDialog

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

        alertDialog = AlertDialog.Builder(applicationContext)
            .setTitle("Title")
            .setMessage("Message")
            .setPositiveButton("OK", object: DialogInterface.OnClickListener {
                override fun onClick(dialog: DialogInterface?, which: Int) {
                    Toast.makeText(applicationContext, "OK", Toast.LENGTH_SHORT).show()
                }
            })
            .setNegativeButton("Cancel", object: DialogInterface.OnClickListener {
                override fun onClick(dialog: DialogInterface?, which: Int) {
                    Toast.makeText(applicationContext, "Cancel", Toast.LENGTH_SHORT).show()
                }
            })
            .setNeutralButton("Neutral", object: DialogInterface.OnClickListener {
                override fun onClick(dialog: DialogInterface?, which: Int) {
                    Toast.makeText(applicationContext, "Neutral", Toast.LENGTH_SHORT).show()
                }
            })
            .create()

        btnShow.setOnClickListener {
            alertDialog.show()
        }
    }

}

 

실행 결과

 

 

 

 

 

 

MainActivity.kt

package com.jwsoft.kotlinproject

import android.content.DialogInterface
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.widget.Toast
import androidx.appcompat.app.AlertDialog
import kotlinx.android.synthetic.main.activity_main.*

class MainActivity : AppCompatActivity() {

    lateinit var alertDialog: AlertDialog

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

        alertDialog = AlertDialog.Builder(this)
            .setTitle("Title")
            .setMessage("Message")
            .setPositiveButton("OK", object: DialogInterface.OnClickListener {
                override fun onClick(dialog: DialogInterface?, which: Int) {
                    Toast.makeText(applicationContext, "OK", Toast.LENGTH_SHORT).show()
                }
            })
            .setNegativeButton("Cancel", object: DialogInterface.OnClickListener {
                override fun onClick(dialog: DialogInterface?, which: Int) {
                    Toast.makeText(applicationContext, "Cancel", Toast.LENGTH_SHORT).show()
                }
            })
            .setNeutralButton("Neutral", object: DialogInterface.OnClickListener {
                override fun onClick(dialog: DialogInterface?, which: Int) {
                    Toast.makeText(applicationContext, "Neutral", Toast.LENGTH_SHORT).show()
                }
            })
            .create()

        btnShow.setOnClickListener {
            alertDialog.show()
        }
    }

}

alertDialog = AlertDialog.Builder(applicationContext) 에서

alertDialog = AlertDialog.Builder(true) 로 수정

 

실행 결과