Remove Divider from NavigationView items

Question

I made a navigation view populated by this .xml:

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


<item android:title="Menu A"
    >
    <menu
       >
        <group
            android:checkableBehavior="single"
            android:orderInCategory="2" 
            android:id="@+id/gr"
            >
            <item
                android:id="@+id/a1"
                android:title="A1"
                />

        </group>

    </menu>
</item>

<item android:title="Menu B"
    android:orderInCategory="3"
    >
    <menu>
        <group android:checkableBehavior="single">
            <item
                android:id="@+id/b1"
                android:title="B1"
                />
            <item
                android:id="@+id/b2"
                android:title="B2"
                />

            <item
                android:id="@+id/b3"
                android:title="B3"
                />
        </group>
    </menu>

</item>

I want to add one item programatically to my NavigationView. I am adding that item with this line of code:

MenuItem item = menu.add(R.id.gr, Menu.NONE, 2, "A2");

Above that item (A2) appears a delimiter. I don't want that delimiter. How can I remove it?

Note: I don't want to put the color of my delimiters transparent. That will make all delimiters disappear.

Answer 1

Add the new item to the SubMenu, not to the Menu. So the delimiter above the item will not appear.

Menu menu = navigationView.getMenu();
MenuItem menuItem = menu.getItem(0);
SubMenu subMenu = menuItem.getSubMenu();
subMenu.add(R.id.gr, Menu.NONE, 2, "A2");
subMenu.setGroupCheckable(R.id.gr, true, true);

Call subMenu.setGroupCheckable(R.id.gr, true, true) if you want to define the checkable behaviour for the group. This should be called after the items of the group have been added.