选项菜单在toolbar下面弹出

在style里面 设置一下就可以了

<resources>

    <!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
        <!-- Customize your theme here. -->
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
        <item name="actionOverflowMenuStyle">@style/Myoption</item>
    </style>
    <style name="Myoption" parent="Base.Widget.AppCompat.Light.PopupMenu.Overflow">
        <item name="overlapAnchor" >false</item>
    </style>
</resources>