导航抽屉预览

Question

这是我的代码

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"


    <group android:checkableBehavior="single">

        <item
            android:id="nav_confidentialite"
            android:icon="@drawable/ic_confidentialite"
            android:title="@string/confidentialite" />
        <item
            android:id="nav_data"
            android:icon="@drawable/ic_data_settings"
            android:title="@string/ModifierProfil" />
        <item
            android:id="nav_search"
            android:icon="@drawable/ic_search_black"
            android:title="@string/Rechercher" />
        <item
            android:id="nav_LogOut"
            android:icon="@drawable/ic_logout"
            android:title="@string/SeDeconnecter" />

    </group>
</menu>

**预览显示此内容**

Drop down list 1

但是当我添加

时

tools:showIn="navigation_view"

预览如下

Drop down list 2