activity_main.xml：

<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.support.design.widget.AppBarLayout
        android:id="@+id/appBar"
        android:layout_width="match_parent"
        android:layout_height="300dip"
        android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar" >

        <!-- app:expandedTitleGravity="left|bottom"扩张后Title位置还可以这么设置 -->

        <android.support.design.widget.CollapsingToolbarLayout
            android:id="@+id/collapsingToolbarLayout"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:layout_scrollFlags="scroll|exitUntilCollapsed"
            app:collapsedTitleGravity="left"
            app:contentScrim="#2196F3"
            app:expandedTitleMarginStart="20dp"
            app:title="zzw" >

            <ImageView
                android:id="@+id/imageView"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                app:layout_collapseMode="parallax"
                app:layout_collapseParallaxMultiplier="0.1"
                android:scaleType="centerCrop"
                android:src="@drawable/bg_default" />

            <android.support.v7.widget.Toolbar
                android:id="@+id/toolbar"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"
                app:layout_collapseMode="pin"
                android:minHeight="?attr/actionBarSize" >
            </android.support.v7.widget.Toolbar>
        </android.support.design.widget.CollapsingToolbarLayout>
    </android.support.design.widget.AppBarLayout>

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

        <android.support.v7.widget.LinearLayoutCompat
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical"
            android:padding="20dip"
            app:divider="?android:attr/listDivider"
            app:dividerPadding="5dp"
            app:showDividers="beginning|middle|end" >

            <TextView
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:padding="50dp"
                android:text="0" />

            <TextView
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:padding="50dp"
                android:text="1" />

            <TextView
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:padding="50dp"
                android:text="2" />

            <TextView
                andro