grouping.
This usage scenario is still very nice
<?xml version="1.0" encoding="utf-8"?>
<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"
tools:context=".MainActivity">
<Button
android:id="@+id/Rightbottom"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="右下角"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent" />
<Button
android:id="@+id/leftBottom"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="左下角"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintStart_toStartOf="parent" />
<Button
android:id="@+id/leftTop"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="左上角"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<Button
android:id="@+id/rightTop"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="右上角"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<Button
android:id="@+id/center"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="中间"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
/>
</androidx.constraintlayout.widget.ConstraintLayout>
We want to hide the three controls below and in the middle at the same time
Add to the control
<androidx.constraintlayout.widget.Group
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:visibility="gone"
app:constraint_referenced_ids="center,leftBottom,rightBottom" />
Just
