layout 디바이스 화면별 가운데 표시할때
res-auto 이용해 자동으로
가운데 표시하자

<androidx.constraintlayout.widget.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"
    android:orientation="vertical">



<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="9"
android:background="#ffffff"
android:gravity="center_vertical"
android:orientation="vertical"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
>
  <TextView
android:id="@+id/massg_time"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="가운데"
android:textColor="#000000"
android:textSize="24sp" />
</LinearLayout>

</androidx.constraintlayout.widget.ConstraintLayout>


#가운데정렬 #안드로이드 #스튜디오