NestedScrollView + Appbar将视图推到顶部

Question

我正在使用viewpager，它具有自己的CollapsingToolbarLayout。 但有时，特定页面的视图有问题（状态栏下方的主页按钮也是如此）。

当我删除工具栏的android：fitsSystemWindows并将边距顶部设置为24dp时，工具栏已修复，但cardview的边距顶部保持错误。

发生了什么事？

Git merge without auto commit

<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:id="@+id/coordinator_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:ignore="MergeRootFrame">

<android.support.design.widget.AppBarLayout
    android:id="@+id/toolbar_det"
    android:layout_width="match_parent"
    android:layout_height="@dimen/app_bar_layout_size"
    app:elevation="@dimen/elevation_app_bar"
    android:fitsSystemWindows="true"
    android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

    <android.support.design.widget.CollapsingToolbarLayout
        android:id="@+id/collapsing_toolbar"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:fitsSystemWindows="true"
        app:expandedTitleMarginEnd="@dimen/expanded_title_margin_end"
        app:expandedTitleMarginStart="@dimen/expanded_title_margin_start"
        app:layout_scrollFlags="scroll"
        app:toolbarId="@id/toolbar">

        <FrameLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:fitsSystemWindows="true">

            <View
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:background="@color/lightPrimaryColor" />

            <ImageView
                android:id="@+id/image_view_photo"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:scaleType="centerCrop"
                android:transitionName="@string/shared_transition" />

            <LinearLayout
                android:id="@+id/background_bar"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_gravity="bottom"
                tools:background="@drawable/gradient_black"
                android:orientation="vertical"
                android:padding="@dimen/default_margin">

                <TextView
                    android:id="@+id/text_view_title"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:fontFamily="sans-serif-medium"
                    android:paddingBottom="@dimen/detail_metabar_title_bottom_padding"
                    android:textColor="@color/white"
                    android:textSize="22sp"
                    android:textStyle="bold" />

                <TextView
                    android:id="@+id/text_view_info"
                    android:fontFamily="sans-serif-condensed"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:textColor="@color/white" />
            </LinearLayout>
        </FrameLayout>

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar_article_detail"
            android:fitsSystemWindows="false"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            app:layout_collapseMode="pin"
            app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />

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

<android.support.v4.widget.NestedScrollView
    android:id="@+id/nestedScrollView"
    android:layout_width="match_parent"
    android:clipToPadding="true"
    android:layout_height="match_parent"
    android:layout_gravity="center_horizontal"
    app:layout_behavior="@string/appbar_scrolling_view_behavior">

    <FrameLayout
        android:layout_width="match_parent"
        android:paddingBottom="16dp"
        android:layout_height="match_parent">

    <android.support.v7.widget.CardView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_margin="@dimen/card_view_margin"
        android:clickable="true"
        android:focusable="true"
        android:layout_marginBottom="16dp"
        android:padding="@dimen/card_padding"
        app:cardElevation="@dimen/cardview_default_elevation">

        <TextView
            android:id="@+id/text_view_body"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_margin="@dimen/body_margin"
            android:textColor="@color/primaryText"
            android:textColorLink="@color/colorAccent"
            tools:textSize="@dimen/text_size_body" />
    </android.support.v7.widget.CardView>

    </FrameLayout>

</android.support.v4.widget.NestedScrollView>

<android.support.design.widget.FloatingActionButton
    android:id="@+id/fab_share"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginEnd="@dimen/fab_margin"
    android:layout_marginRight="@dimen/fab_padding"
    android:contentDescription="@string/action_share"
    android:src="@drawable/ic_share"
    app:elevation="@dimen/elevation_fab"
    app:fabSize="normal"
    app:layout_anchor="@id/toolbar_det"
    app:layout_anchorGravity="bottom|right|end"
    tools:background="?android:attr/selectableItemBackgroundBorderless" />
</android.support.design.widget.CoordinatorLayout>