AlertDialog in Android — The Complete Guide

This guide covers everything you need to know about AlertDialog in Android — from basic usage to custom layouts. All examples are in Kotlin.

Basic AlertDialog

The simplest AlertDialog has a title, a message, and buttons. Android supports three button types:

Positive — confirms an action (e.g., “OK”, “Save”)
Negative — cancels or dismisses (e.g., “Cancel”)
Neutral — an alternative action (e.g., “Later”, “Learn More”)

AlertDialog.Builder(this)
    .setTitle("Confirm Delete")
    .setMessage("Are you sure you want to delete this item?")
    .setPositiveButton("Delete") { _, _ ->
        // handle delete
    }
    .setNegativeButton("Cancel") { dialog, _ ->
        dialog.dismiss()
    }
    .show()

You can also add an icon next to the title:

AlertDialog.Builder(this)
    .setTitle("Warning")
    .setMessage("This action cannot be undone.")
    .setIcon(R.drawable.ic_warning)
    .setPositiveButton("OK", null)
    .show()

To prevent the dialog from being dismissed when the user taps outside or presses back:

AlertDialog.Builder(this)
    .setTitle("Important")
    .setMessage("You must accept the terms to continue.")
    .setCancelable(false)
    .setPositiveButton("Accept") { _, _ ->
        // proceed
    }
    .show()

Selection Dialogs

Multi-choice (Checkboxes)

Use setMultiChoiceItems() when the user can select multiple options.

val items = arrayOf("Kotlin", "Java", "Python", "Go")
val checkedItems = booleanArrayOf(false, false, false, false)
val selectedItems = mutableListOf<String>()

AlertDialog.Builder(this)
    .setTitle("Select Languages")
    .setMultiChoiceItems(items, checkedItems) { _, index, isChecked ->
        if (isChecked) {
            selectedItems.add(items[index])
        } else {
            selectedItems.remove(items[index])
        }
    }
    .setPositiveButton("Done") { _, _ ->
        // use selectedItems
    }
    .setNegativeButton("Cancel", null)
    .show()

The checkedItems array tracks the state of each checkbox. If you reopen the dialog, previously selected items stay checked.

Single-choice (Radio Buttons)

Use setSingleChoiceItems() when only one option can be selected.

val themes = arrayOf("Light", "Dark", "System Default")
var selectedIndex = 0

AlertDialog.Builder(this)
    .setTitle("Choose Theme")
    .setSingleChoiceItems(themes, selectedIndex) { _, index ->
        selectedIndex = index
    }
    .setPositiveButton("Apply") { _, _ ->
        // apply themes[selectedIndex]
    }
    .setNegativeButton("Cancel", null)
    .show()

The second parameter of setSingleChoiceItems() is the initially selected index. Pass -1 if nothing should be pre-selected.

Note: Don’t use setMessage() together with choice items — the message takes priority and the list won’t show.

Custom Layout from XML

For anything beyond buttons and lists, create a custom XML layout and inflate it into the dialog.

The layout file

Create res/layout/dialog_login.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:orientation="vertical"
    android:padding="24dp">

    <com.google.android.material.textfield.TextInputLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Username"
        style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox">

        <com.google.android.material.textfield.TextInputEditText
            android:id="@+id/etUsername"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:inputType="text" />
    </com.google.android.material.textfield.TextInputLayout>

    <com.google.android.material.textfield.TextInputLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="12dp"
        android:hint="Password"
        app:passwordToggleEnabled="true"
        style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox">

        <com.google.android.material.textfield.TextInputEditText
            android:id="@+id/etPassword"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:inputType="textPassword" />
    </com.google.android.material.textfield.TextInputLayout>

</LinearLayout>

Inflating and using it

val dialogView = layoutInflater.inflate(R.layout.dialog_login, null)
val etUsername = dialogView.findViewById<TextInputEditText>(R.id.etUsername)
val etPassword = dialogView.findViewById<TextInputEditText>(R.id.etPassword)

AlertDialog.Builder(this)
    .setTitle("Login")
    .setView(dialogView)
    .setCancelable(false)
    .setPositiveButton("Login") { _, _ ->
        val username = etUsername.text.toString()
        val password = etPassword.text.toString()
        // handle login
    }
    .setNegativeButton("Cancel", null)
    .show()

The key method is setView() — it takes any View and places it between the title and the buttons.

Custom Layout Programmatically

Sometimes you don’t want to create a separate XML file for a simple custom layout. You can build views in code:

val layout = LinearLayout(this).apply {
    orientation = LinearLayout.VERTICAL
    setPadding(48, 32, 48, 16)
}

val etName = EditText(this).apply {
    hint = "Enter your name"
    inputType = InputType.TYPE_CLASS_TEXT
    isSingleLine = true
}

val etEmail = EditText(this).apply {
    hint = "Enter your email"
    inputType = InputType.TYPE_TEXT_VARIATION_EMAIL_ADDRESS
    isSingleLine = true
}

layout.addView(etName)
layout.addView(etEmail)

AlertDialog.Builder(this)
    .setTitle("Contact Info")
    .setView(layout)
    .setPositiveButton("Save") { _, _ ->
        val name = etName.text.toString()
        val email = etEmail.text.toString()
        // handle save
    }
    .setNegativeButton("Cancel", null)
    .show()

This approach works for simple layouts. For anything with multiple nested views, Material components, or constraints — use XML. It’s easier to read and maintain.

Customizing Buttons

Changing button colors

You can customize button appearance, but there’s a catch — you must call show() first, then access the buttons. Calling getButton() before show() returns null.

val dialog = AlertDialog.Builder(this)
    .setTitle("Delete Account")
    .setMessage("This will permanently delete your account and all data.")
    .setPositiveButton("Delete", null)
    .setNegativeButton("Cancel", null)
    .create()

dialog.show()

dialog.getButton(DialogInterface.BUTTON_POSITIVE).apply {
    setTextColor(ContextCompat.getColor(context, android.R.color.holo_red_dark))
}

dialog.getButton(DialogInterface.BUTTON_NEGATIVE).apply {
    setTextColor(ContextCompat.getColor(context, android.R.color.darker_gray))
}

Overriding button click behavior

By default, clicking any button dismisses the dialog. To prevent this — for example, to validate input before dismissing — set the click listener after show():

val dialogView = layoutInflater.inflate(R.layout.dialog_login, null)
val etUsername = dialogView.findViewById<TextInputEditText>(R.id.etUsername)
val etPassword = dialogView.findViewById<TextInputEditText>(R.id.etPassword)

val dialog = AlertDialog.Builder(this)
    .setTitle("Login")
    .setView(dialogView)
    .setPositiveButton("Login", null) // null — we'll override this
    .setNegativeButton("Cancel", null)
    .create()

dialog.show()

dialog.getButton(DialogInterface.BUTTON_POSITIVE).setOnClickListener {
    val username = etUsername.text.toString()
    val password = etPassword.text.toString()

    if (username.isBlank() || password.isBlank()) {
        // don't dismiss — show error
        if (username.isBlank()) etUsername.error = "Username required"
        if (password.isBlank()) etPassword.error = "Password required"
    } else {
        // valid input — proceed and dismiss
        handleLogin(username, password)
        dialog.dismiss()
    }
}

The trick is passing null as the click listener in setPositiveButton(), then setting a custom OnClickListener after show(). This gives you full control over when the dialog dismisses.

Quick Reference

What you need	Method
Simple message with buttons	`setTitle()` + `setMessage()` + `setPositiveButton()`
Checkbox list	`setMultiChoiceItems()`
Radio button list	`setSingleChoiceItems()`
Custom layout (XML)	`setView(layoutInflater.inflate(...))`
Custom layout (code)	`setView(linearLayout)`
Prevent dismiss on outside tap	`setCancelable(false)`
Style buttons	`dialog.show()` then `dialog.getButton(...)`
Override dismiss behavior	Set `null` listener, override after `show()`

Download Source Code

View on GitHub krrishnaaaa/create-alertdialog-android View on GitHub krrishnaaaa/custom-alertdialog-programmatically