如何在CoordinatorLayout中的Viewpager下面获取Adview

此刻AdView出现在里面ViewPager所以它会阻止应用程序中的内容。我怎样才能得到AdView出现在下面ViewPager而不是在里面。

我试过把AdView in a RelativeLayout以下ViewPager但随后AdView根本不显示。

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:ads="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="com.candyx.testapp.Activity">

<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/main_content"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@drawable/main_button_background">

        <android.support.v7.widget.Toolbar
            xmlns:android="http://schemas.android.com/apk/res/android"
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            app:layout_scrollFlags="scroll|enterAlways"/>

        <android.support.design.widget.TabLayout
            android:id="@+id/tabs"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:tabMode="scrollable"
            app:tabGravity="fill"
            app:tabIndicatorColor="@color/colorTabIndicator"
            app:tabIndicatorHeight="3dp"/>

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


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

    <com.google.android.gms.ads.AdView
        android:id="@+id/adView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        ads:adSize="BANNER"
        ads:adUnitId="@string/banner_ad_unit_id"
        android:layout_gravity="center|bottom"/>

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

</LinearLayout>

你可以加ViewPager and AdView inside RelativeLayout并指定android:layout_above="@+id/adView"财产给ViewPager以便adView不阻止ViewPager内容。

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:ads="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.candyx.testapp.Activity">

    <android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:id="@+id/main_content"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_above="@+id/adView">

        <android.support.design.widget.AppBarLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="@drawable/main_button_background">

            <android.support.v7.widget.Toolbar
                xmlns:android="http://schemas.android.com/apk/res/android"
                android:id="@+id/toolbar"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"
                app:layout_scrollFlags="scroll|enterAlways"/>

            <android.support.design.widget.TabLayout
                android:id="@+id/tabs"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                app:tabMode="scrollable"
                app:tabGravity="fill"
                app:tabIndicatorColor="@color/colorTabIndicator"
                app:tabIndicatorHeight="3dp"/>

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

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

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

    <com.google.android.gms.ads.AdView
        android:id="@id/adView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        ads:adSize="BANNER"
        ads:adUnitId="@string/banner_ad_unit_id"
        android:layout_gravity="center|bottom"
        android:layout_alignParentBottom="true"/>

</RelativeLayout>