Android 9 Development Cookbook - Third Edition

How to do it...

We will start by creating a UI with an EditText to enter a phone number and three buttons: Block, Unblock, and isBlocked. To start, open activity_main.xml and follow these steps:

1. Replace the existing layout with the following XML code:

<?xml version="1.0" encoding="utf-8"?><RelativeLayout    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"    tools:context=".MainActivity">    <EditText        android:id="@+id/editTextNumber"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:inputType="phone"        android:ems="10"        android:layout_alignParentTop= ...