Android滑动到顶部悬停

http://www.open-open.com/lib/view/open1473834348870.html

<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"
    android:fitsSystemWindows="true"
    tools:context="com.peipei.app.MainActivity">

    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="250dp">

        <android.support.design.widget.CollapsingToolbarLayout
            app:layout_scrollFlags="scroll"
            app:contentScrim="#000000"
            android:layout_width="match_parent"
            android:layout_height="220dp">

            <TextView
                android:text="banner区域"
                android:gravity="center"
                android:textColor="#ffffff"
                android:background="#987545"
                android:layout_width="match_parent"
                android:layout_height="220dp"/>

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

        <TextView
            android:gravity="center"
            android:layout_width="match_parent"
            android:layout_height="30dp"
            android:text="悬浮的部分"/>

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

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

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_margin="@dimen/text_margin"
                android:text="@string/large_text"/>

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

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