我正在使用带有底部导航视图和中间的片段的折叠工具栏布局。当折叠工具栏的标题展开时，由于某种原因，底部导航视图下方有一个小间隙。我已经尝试修改fitsSystemWindows标签，但它没有解决问题。
但是，当标题折叠时，间隙会自动消失。
这是我正在使用的布局 xml 文件：
<?xml version="1.0" encoding="utf-8"?>
<layout 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">
<data>
<variable
name="viewModel"
type="LandingViewModel" />
</data>
<androidx.constraintlayout.widget.ConstraintLayout
android:id="@+id/layout_base"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:animateLayoutChanges="true"
android:background="?attr/colorSurface">
<androidx.coordinatorlayout.widget.CoordinatorLayout
android:layout_width="match_parent"
android:layout_height="0dp"
app:layout_constraintBottom_toTopOf="@id/bottomNavigation"
app:layout_constraintTop_toTopOf="parent">
<com.google.android.material.appbar.AppBarLayout
android:id="@+id/layout_app_bar"
android:layout_width="match_parent"
android:layout_height="@dimen/app_bar_height"
android:background="?attr/colorSurface"
android:fitsSystemWindows="true"
app:expanded="true">
<com.google.android.material.appbar.CollapsingToolbarLayout
android:id="@+id/layout_toolbar"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
app:expandedTitleMarginStart="@dimen/margin_normal"
android:minHeight="?attr/actionBarSize"
app:contentScrim="?attr/colorSurface"
app:elevation="0dp"
app:layoutDescription="@xml/home_fragment_motion_scene"
app:layout_scrollFlags="scroll|exitUntilCollapsed"
app:toolbarId="@+id/toolbar"
tools:ignore="ExtraText">
<androidx.appcompat.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorSurface"
android:elevation="0dp"
app:layout_collapseMode="pin" />
</com.google.android.material.appbar.CollapsingToolbarLayout>
</com.google.android.material.appbar.AppBarLayout>
<androidx.fragment.app.FragmentContainerView
android:id="@+id/nav_host_fragment"
android:name="androidx.navigation.fragment.NavHostFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:defaultNavHost="true"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
app:navGraph="@navigation/landing_navigation" />
</androidx.coordinatorlayout.widget.CoordinatorLayout>
<com.google.android.material.bottomnavigation.BottomNavigationView
android:id="@+id/bottomNavigation"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="?attr/colorSurface"
android:clipChildren="false"
app:itemHorizontalTranslationEnabled="false"
app:itemIconTint="@android:color/white"
app:itemRippleColor="@null"
app:itemTextColor="@android:color/white"
app:labelVisibilityMode="unlabeled"
app:layout_constraintBottom_toBottomOf="parent"
app:menu="@menu/landing_bottom_navigation">
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="@dimen/landing_bottom_nav_layout_height"
android:layout_gravity="center"
android:background="?attr/colorSurface">
<CustomAnimationButton
android:id="@+id/btnTemplates"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:icon="@drawable/ic_baseline_templates_24"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toLeftOf="@+id/icCreateProject"
app:layout_constraintTop_toTopOf="parent"
app:selected="true"
app:titleTextSize= "@dimen/text_size_12sp"
app:title="@string/fgm_home_menu_title"
app:updated="true" />
<androidx.constraintlayout.widget.ConstraintLayout
android:id="@+id/icCreateProject"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:translationY="-15dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent">
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:contentDescription="@string/cd_create_something_icon"
android:src="@drawable/ic_baseline_add_purple_outline"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<ImageView
android:id="@+id/newTemplateFab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:contentDescription="@string/cd_create_something_icon"
android:src="@drawable/selector_ic_add"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
<CustomAnimationButton
android:id="@+id/btnStories"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:icon="@drawable/ic_baseline_my_stories_24"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toRightOf="@+id/icCreateProject"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:selected="false"
app:titleTextSize= "@dimen/text_size_12sp"
app:title="@string/txt_my_stories"
app:updated="false" />
</androidx.constraintlayout.widget.ConstraintLayout>
</com.google.android.material.bottomnavigation.BottomNavigationView>
<!--blur background for backup template-->
<ImageView
android:id="@+id/ivBlurBackground"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:contentDescription="@string/cd_blur_bg"
android:elevation="8dp"
android:visibility="gone" />
</androidx.constraintlayout.widget.ConstraintLayout>