activity_maintc.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="net.oimtrust.MainActivity">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="24sp"
        android:gravity="center"
        android:textStyle="bold"
        android:textColor="@color/colorYellow"
        android:text="@string/loading"/>

    <ProgressBar
        style="?android:attr/progressBarStyleLarge"
        android:layout_width="154dp"
        android:layout_height="wrap_content"
        android:id="@+id/progressBar"
        android:layout_gravity="center_horizontal"
        android:indeterminate="false"
        />

</LinearLayout>