如何在ScrollView上滚动时隐藏浮动操作按钮？Android - Kotlin

<ScrollView
    android:id="@+id/scrollView"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <!-- 可滚动的内容 -->

</ScrollView>

<FloatingActionButton
    android:id="@+id/floatingActionButton"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="bottom|end"
    android:layout_margin="16dp"
    android:src="@drawable/ic_action_button"
    android:visibility="visible" />

val scrollView: ScrollView = findViewById(R.id.scrollView)
val floatingActionButton: FloatingActionButton = findViewById(R.id.floatingActionButton)

scrollView.viewTreeObserver.addOnScrollChangedListener {
    if (scrollView.scrollY > 0) {
        floatingActionButton.hide()
    } else {
        floatingActionButton.show()
    }
}