Unknown type on implementing NavigationView

[Quogey]

So, i was trying to create a fragments on Drawer but when i tried implementing onNavigationItemSelectedListener i encountered some errors, the (this) in navigationView. setNavigationItemSelectedListener(this); gives errors.

English is not my first language and Thanks in advance.

[Ali]

Try a capital letter “o” in your implementation:
NavigationView.OnNavigationItemSelectedListener