How to centre a parent ViewGroup?

Question

I have a parent ConstraintLayout in my fragment.xml:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="400dp"
    android:maxHeight="400dp"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintBottom_toBottomOf="parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:background="@color/colorPopupBackground"
    android:fadeScrollbars="false"
    android:id="@+id/profile_layout"
    android:elevation="1dp">

as you can see i've set a maxHeight and constrained it on every side - so you would think it should centre vertically on the screen. However the ConstraintLayout sits on the top vertically.

Any idea?

Does this answer your question? [ConstraintLayout views in top left corner](https://stackoverflow.com/questions/42594033/constraintlayout-views-in-top-left-corner) — string.Empty, Nov 13 '19 at 09:12
Try using `android:layout_gravity="center"` to make it center align — Md. Asaduzzaman, Nov 13 '19 at 09:23
Also clear your requirements. It's not clear from your description — Md. Asaduzzaman, Nov 13 '19 at 09:25
`android:layout_gravity="center"` doesn't work, it still aligns to the top vertically . @Md.Asaduzzaman — Zorgan, Nov 13 '19 at 10:01
Are you trying to achieve `profile_layout` center align, right? or its content? — Md. Asaduzzaman, Nov 13 '19 at 10:03
Center the parent view (`ConstraintLayout`), not its children. — Zorgan, Nov 13 '19 at 10:32
Then put is inside another ConstraintLayout and set the root one `match_parent` to it's `width` and `height` — Md. Asaduzzaman, Nov 13 '19 at 10:35

score 0 · Answer 1 · answered Nov 13 '19 at 09:15

Just remove bottom constraint because when you set both side constraint and set custom width then it will be center of both constraint, SO update your code like bellow

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="400dp"
    android:maxHeight="400dp"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintEnd_toEndOf="parent"

    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:background="@color/colorPopupBackground"
    android:fadeScrollbars="false"
    android:id="@+id/profile_layout"
    android:elevation="1dp">

How to centre a parent ViewGroup?

1 Answers1