底部导航活动模板中标题和片段之间的差距

Question

I was checking out the Android Studio's Bottom Navigation Activity project template, and found that that is a gap between the 'title' and 'home fragment'. The only change I added was a android:background="@color/colorAccent" to the fragment_home.xml to highlight the gap?

Is there any use of this gap? How to get rid of this gap?

Answer 1

Found the cause. It is due to the android:paddingTop="?attr/actionBarSize" found in 'activity_main.xml'.

<?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"
  android:id="@+id/container"
  android:layout_width="match_parent"
  android:layout_height="match_parent"

  android:paddingTop="?attr/actionBarSize"

  >