Android how to achieve up-slide hiding, slide to show the title bar and FAB?

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout 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"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:context=".MainActivity">

    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/AppTheme.AppBarOverlay">


        <com.arlib.floatingsearchview.FloatingSearchView
            android:id="@+id/search_bar"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:layout_scrollFlags="scroll">
        </com.arlib.floatingsearchview.FloatingSearchView>

        <android.support.design.widget.TabLayout
            android:id="@+id/tab_layout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:layout_scrollFlags="scroll"
            app:tabTextAppearance="@style/CustomTabLayoutTextAppearance">

            <android.support.design.widget.TabItem
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="AAA" />

            <android.support.design.widget.TabItem
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="BBB" />

            <android.support.design.widget.TabItem
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="CCC" />

        </android.support.design.widget.TabLayout>

    </android.support.design.widget.AppBarLayout>

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom|end"
        android:layout_margin="@dimen/fab_margin"
        app:elevation="5dp"
        app:srcCompat="@drawable/ic_add_black_24dp" />

    <ListView
        android:id="@+id/list_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:dividerHeight="7.5dp"
        android:paddingTop="10dp"
        app:layout_behavior="@string/appbar_scrolling_view_behavior"></ListView>


</android.support.design.widget.CoordinatorLayout>

above is the layout file, the title bar is made up of github"s open source search components FloatingSearchView and TabLayout, and below is a ListView. The information found by
is said to be app:layout_scrollFlags= "scroll" , and it can be skimmed up and hidden and displayed downwards.
but there is no response anyway. What is the problem?

Android

Apr.15,2021