activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:layout_margin="@dimen/activity_horizontal_margin">

    <Button
        android:id="@+id/alertDialog_1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="AlertDialog 1"/>

    <Button
        android:id="@+id/alertDialog_2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="AlertDialog 2"/>

    <Button
        android:id="@+id/alertDialog_3"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="AlertDialog 3"/>
</LinearLayout>