摺疊toolbar

<?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"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".fragment.OneFragment">
    <!--CoordinatorLayout頂層佈局，調度協調子佈局-->
    <android.support.design.widget.AppBarLayout
        android:id="@+id/appbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:fitsSystemWindows="true"
        >

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="100dp"
            android:background="#ff6600"
            app:layout_scrollFlags="scroll|enterAlways|snap"
            >

            <TextView
                android:id="@+id/tv_toolBarTitle"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_gravity="left"
                android:layout_marginTop="0dp"
                android:text="AndroidFun"
                android:textColor="#FFF"
                android:textSize="25sp" />
        </android.support.v7.widget.Toolbar>

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

            <android.support.design.widget.TabLayout
                android:id="@+id/tab"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_toLeftOf="@+id/img"
                android:layout_toStartOf="@+id/img"
                android:layout_weight="9"
                android:background="#ff6600"
                app:tabMode="scrollable"></android.support.design.widget.TabLayout>

            <ImageView
                android:id="@+id/add"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_alignParentRight="true"
                android:layout_alignParentTop="true"
                android:layout_weight="1"
                android:background="#ff6600"
                android:src="@drawable/addphoto" />
        </LinearLayout>
    </android.support.design.widget.AppBarLayout>

    <android.support.v4.view.ViewPager
        android:id="@+id/view_pager"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_behavior="@string/appbar_scrolling_view_behavior">

    </android.support.v4.view.ViewPager>



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