<?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout 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=".views.QRcodeReadingActivity"> <TextView android:id="@+id/QRcodeResult" android:layout_width="0dp" android:layout_height="wrap_content" android:gravity="center" android:text="aaaaaaaaaaaaaaaa" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintHorizontal_bias="0.5" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/result" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginTop="8dp" android:layout_marginBottom="8dp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintHorizontal_bias="0.5" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toBottomOf="@+id/QRcodeResult" /> </android.support.constraint.ConstraintLayout>