How to select the first item in a navigation drawer and open a fragment on application start

Question

I have created MainActivity with NavigationView. When Activity is opened I want to automatically select the first item in the navigation d

Answer 1

in menu.xml remember to mention android:checkable="true" for single item and android:checkableBehavior="single" for a group of items.

<item
        android:id="@+id/pos_item_help"
        android:checkable="true"
        android:title="Help" />

    <group
        android:id="@+id/group"
        android:checkableBehavior="single">
        <item
            android:id="@+id/menu_nav_home"
            android:icon="@drawable/ic_home_black_24dp"
            android:title="@string/menu_nav_home" />
    </group>

then inside NavigationItemSelectedListener use setCheckedItem(R.id.item_id_in_menu) to make it selected.

@Override
    public boolean onNavigationItemSelected(@NonNull MenuItem item) {
        switch (item.getItemId()) {

            case R.id.pos_item_pos:
                navigationView.setCheckedItem(R.id.pos_item_pos);
                break;
            case R.id.pos_item_orders:
                navigationView.setCheckedItem(R.id.pos_item_orders);
                break;
            default:
        }
        return true;
    }

And you do not have to do the dirty task of managing the selected item anymore. navigationView manages it by self.

Answer 2

just add this code in onCreate method:

FragmentTransaction ftrans = getFragmentManager().beginTransaction();
ftrans.replace(R.id.container, <yourfragment>).commit();

Work for me !