向上滚动时Android折叠工具栏显示工具栏

Question

在我的应用程序中，我有一个详细信息页面，其中包含折叠工具栏布局和下方的 litview。当我向上滚动时我只需要显示工具栏，当我移动到 ListView 的顶部时显示完整布局。

像这样:

这是我的代码，但它不起作用:

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

<android.support.design.widget.AppBarLayout
    android:id="@+id/app_bar_layout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    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:contentScrim="?attr/colorPrimary"
        app:expandedTitleMarginEnd="64dp"
        app:expandedTitleMarginStart="48dp"
        app:layout_scrollFlags="scroll">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:minHeight="?attr/actionBarSize"
            app:layout_collapseMode="pin"
            app:layout_scrollFlags="scroll|enterAlways"
            app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />

        <ImageView
            android:id="@+id/image"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:fitsSystemWindows="true"
            android:scaleType="centerCrop"
            app:layout_collapseMode="parallax" />

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

<android.support.v4.widget.NestedScrollView
    android:id="@+id/scroll"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:clipToPadding="false"
    app:layout_behavior="@string/appbar_scrolling_view_behavior">

    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <android.support.v7.widget.CardView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="24dp"
            app:cardElevation="@dimen/spacing_medium"
            app:cardUseCompatPadding="true">

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:orientation="vertical">

                <TextView
                    android:id="@+id/title"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginLeft="@dimen/spacing_large"
                    android:layout_marginRight="@dimen/spacing_large"
                    android:layout_marginTop="@dimen/spacing_large"
                    android:textAppearance="@style/TextAppearance.AppCompat.Headline" />

                <TextView
                    android:id="@+id/description"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_margin="@dimen/spacing_large"
                    android:text="@string/lorem_ipsum"
                    android:textAppearance="@style/TextAppearance.AppCompat.Body1" />

            </LinearLayout>
        </android.support.v7.widget.CardView>
    </FrameLayout>
</android.support.v4.widget.NestedScrollView>

<android.support.design.widget.FloatingActionButton
    android:id="@+id/fab"
    style="@style/FabStyle"
    app:layout_anchor="@id/app_bar_layout"
    app:layout_anchorGravity="bottom|right|end" />

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

我正在为工具栏使用 app:layout_scrollFlags="scroll|enterAlways"，但它不起作用。有人可以帮我解决这个问题吗？

Answer 1

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

    <android.support.design.widget.AppBarLayout
        android:id="@+id/app_bar_layout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        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:contentScrim="?attr/colorPrimary"
            app:expandedTitleGravity="center"
            app:expandedTitleTextAppearance="@style/TextAppearance.AppCompat.Title"
            app:layout_scrollFlags="scroll|enterAlways|enterAlwaysCollapsed">

            <android.support.v7.widget.Toolbar
                android:id="@+id/toolbar"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"
                android:minHeight="?attr/actionBarSize"
                app:layout_scrollFlags="scroll|enterAlways"
                app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />

            <RelativeLayout
                android:layout_width="match_parent"
                android:layout_height="192dp"
                android:background="#34D043">

                <LinearLayout
                    android:id="@+id/ce"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_centerInParent="true"
                    android:layout_gravity="center"
                    android:gravity="center"
                    android:orientation="vertical">

                    <ImageView
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_marginBottom="48dp"
                        android:src="@drawable/ic_transportation" />
                </LinearLayout>
            </RelativeLayout>
        </android.support.design.widget.CollapsingToolbarLayout>
    </android.support.design.widget.AppBarLayout>

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recycler_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_behavior="@string/appbar_scrolling_view_behavior" />

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

这是工作示例，thx krossovochkin他的回答