activity_main.xml

<?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:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:id="@+id/edit"
        android:ems="10"
        android:hint="Type Your Message"
        android:textColorHint="#157b00"
        android:background="#ff0"
        android:textColorHighlight="#f00"
        android:textCursorDrawable="@null"
        android:inputType="phone"
        />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Display Text"
        android:id="@+id/btn"
        android:layout_centerHorizontal="true"
        android:layout_below="@id/edit"
        android:layout_marginTop="10sp"
        />

</RelativeLayout>