如何引用MenuItem click?

我有个问题。我不知道如何在抽屉里获取我的列表视图的引用。

我有一个抽屉布局,有导航视图和菜单。

当我点击时,如何显示附带通知的布局?

navView = (NavigationView) findViewById(R.id.nav_view);
View navHeader = navView.getHeaderView(0);
TextView usuario_header = (TextView) navHeader.findViewById(R.id.username);
TextView correo_header = (TextView) navHeader.findViewById(R.id.emailNavegador);

布局del activity_principal。

<?xml version="1.0" encoding="utf-8"?> <android.support.v4.widget.DrawerLayout 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:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context=".PrincipalActivity">
<!-- Contenido Principal -->
<include layout="@layout/main_content" />
<!-- Menú Deslizante -->
<android.support.design.widget.NavigationView
    android:id="@+id/nav_view"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:layout_gravity="start"
    android:fitsSystemWindows="true"
    app:headerLayout="@layout/nav_header"
    app:menu="@menu/nav_menu" /></android.support.v4.widget.DrawerLayout>

布局de main_content

<LinearLayout 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:orientation="vertical">
<android.support.v7.widget.Toolbar
    android:id="@+id/toolbar"
    android:layout_width="match_parent"
    android:layout_height="?attr/actionBarSize"
    android:background="?attr/colorPrimary"
    android:theme="@style/ThemeOverlay.AppCompat.Dark"
    app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />
<RelativeLayout
    android:id="@+id/main_content"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >
    <TextView
        android:text="Holis"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_alignParentStart="true"
        android:layout_marginStart="148dp"
        android:layout_marginTop="58dp"
        android:id="@+id/textMain" />
</RelativeLayout></LinearLayout>

导航头布局

<?xml version="1.0" encoding="utf-8"?><LinearLayout 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="@dimen/header_height"
android:background="@drawable/material_background3"
android:gravity="bottom"
android:orientation="vertical"
android:padding="@dimen/header_left_padding"
android:theme="@style/ThemeOverlay.AppCompat.Dark"
android:id="@+id/header">
<!-- Imagen de perfil -->
<de.hdodenhof.circleimageview.CircleImageView
    android:id="@+id/circle_image"
    android:layout_width="@dimen/perfil_image_size"
    android:layout_height="@dimen/perfil_image_size"
    android:layout_marginBottom="16dp"
    android:scaleType="centerCrop"
    android:src="@drawable/pacoalba"
    app:border_color="@android:color/white"
    app:border_width="1dp" />
<!-- Nombre de Usuario -->
<TextView
    android:id="@+id/username"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:textAppearance="@style/TextAppearance.AppCompat.Body1"
    android:textStyle="bold" />
<!-- Correo de la cuenta -->
<TextView
    android:id="@+id/emailNavegador"
    style="@style/Widget.AppCompat.Spinner"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:textAppearance="@style/TextAppearance.AppCompat.Body1" /></LinearLayout>

菜单

<?xml version="1.0" encoding="utf-8"?><menu xmlns:android="http://schemas.android.com/apk/res/android">
<group android:checkableBehavior="single">
    <item
        android:id="@+id/nav_noticias"
        android:checked="true"
        android:icon="@drawable/ic_libro"
        android:title="@string/noticias_item" />
    <item
        android:id="@+id/nav_sesion"
        android:icon="@drawable/ic_sesion"
        android:title="@string/sesion_item" />
    <item
        android:id="@+id/nav_mapa"
        android:icon="@drawable/ic_mapa"
        android:title="@string/mapa_item" />
    <item
        android:id="@+id/nav_rutas"
        android:icon="@drawable/ic_rutas"
        android:title="@string/rutas_item" />
    <item
        android:id="@+id/nav_eventos"
        android:icon="@drawable/ic_eventos"
        android:title="@string/eventos_item" />
    <item
        android:id="@+id/nav_alertas"
        android:icon="@drawable/ic_alertas"
        android:title="@string/alertas_item" />
    <item
        android:id="@+id/nav_multimedia"
        android:icon="@drawable/ic_multimedia"
        android:title="@string/multimedia_item" />
    <!-- Sección de configuración -->
    <item
        android:id="@+id/configuration_section"
        android:title="@string/configuracion_item">
        <menu>
            <item
                android:id="@+id/nav_log_out"
                android:icon="@android:drawable/ic_lock_power_off"
                android:title="@string/log_out_item" />
        </menu>
    </item>
</group>

非常感谢!