Android-在SubMenu中查找项目的ID

Question

I use Navigation activities for moving from one Activity to another. And I want to add submenu to menu of NavigationView< but can't find way to find id og item in submenu.

    <menu>    
<item android:title="Communicate">
    <menu>
        <item android:id="@+id/about_us" android:icon="@android:drawable/ic_menu_share"
            android:title="About us" />
    </menu>
</item></menu>

@Override
public boolean onNavigationItemSelected(MenuItem item) {
    // Handle navigation view item clicks here.
    int id = item.getItemId();

    switch (id) {
        case R.id.nav_order: {
            break;
        }
        case R.id.nav_search: {
            break;
        }
    }

    return true;
}

I want to add: case R.id.about_us . But Android Studio can't find this id. How can i make it and what i do wrong?

Answer 1

Your code worked fine for me. There is one thing missing in your menu:

<menu xmlns:android="http://schemas.android.com/apk/res/android"/> <!--the xmlns is missing -->
</menu>

Answer 2

try to write like this:

 The drawer itesm below have been classified into groups

    <group
        android:id="@+id/group_1"
        android:checkableBehavior="single">
        <item
            android:id="@+id/navigation_item_1"
            android:icon="@drawable/ic_number_0"
            android:title="@string/navigation_item_1" />
        <item
            android:id="@+id/navigation_item_2"
            android:icon="@drawable/ic_number_1"
            android:title="@string/navigation_item_2" />
    </group>
    <group
        android:id="@+id/group_2"
        android:checkableBehavior="single">
        <item
            android:id="@+id/navigation_item_3"
            android:icon="@drawable/ic_number_2"
            android:title="@string/navigation_item_3" />
        <item
            android:id="@+id/navigation_item_4"
            android:icon="@drawable/ic_number_3"
            android:title="@string/navigation_item_4" />
    </group>
    <group
        android:id="@+id/group_3"
        android:checkableBehavior="single">
        <item
            android:id="@+id/navigation_item_5"
            android:icon="@drawable/ic_number_4"
            android:title="@string/navigation_item_5" />
    </group>

    OR
    The drawer items below have been categorized according to headers
    <item
        android:id="@+id/navigation_item_1"
        android:icon="@drawable/ic_number_0"
        android:title="@string/navigation_item_1">
        <menu>
            <item
                android:id="@+id/navigation_item_2"
                android:icon="@drawable/ic_number_1"
                android:title="@string/navigation_item_2" />
            <item
                android:id="@+id/navigation_item_3"
                android:icon="@drawable/ic_number_2"
                android:title="@string/navigation_item_3" />
        </menu>
    </item>

    <item
        android:id="@+id/navigation_item_4"
        android:icon="@drawable/ic_number_3"
        android:title="@string/navigation_item_4">
        <menu>
            <item
                android:id="@+id/navigation_item_5"
                android:icon="@drawable/ic_number_4"
                android:title="@string/navigation_item_5" />
        </menu>

</item>