如何动态添加 NavigationView 菜单？

Question

So, I would like add menu items to navigationView. The idea is that, there are Projects, and every project belongs to a group. So the group count can be from 1 to N.

These groups are stored in Room database, thease groups don't change at run time, so it is not necessary to invalidate/reset navigation view.

I created a main fragment whic is called Projects, when the user clicks the generated project group menu items, I would like to navigate to the Projects fragment, but with different projectGroupId because of the filtering.

Althought I found the solution for creating menu items, but I don't know how to handle the click event, and how to highlight the menu item like a standard static menu item.

Main Activity navigation view
    private fun setUpNavigation() {
        val navController = findNavController(R.id.nav_host_fragment_content_main)
        setSupportActionBar(binding.appBarMain.toolbar)

        val menuItems = mutableListOf(
            R.id.nav_home, R.id.nav_calendar, R.id.nav_project_browser
        )

        appBarConfiguration = AppBarConfiguration(
            menuItems.toSet(),
            binding.drawerLayout
        )

        setCounterValueToMenuItem(binding.navView.menu.findItem(R.id.nav_home),2)

        setupActionBarWithNavController(navController, appBarConfiguration)
        binding.navView.setupWithNavController(navController)
    }

Generate menu method
rivate fun addExtraMenu(){
        val navView = binding.navView
        val menu = navView.menu
        val subMenu = menu.addSubMenu("Custom menus")

        subMenu.add(0,0,0,"Menu 1",)
        setMenuItemActionView(subMenu[0])

        subMenu.add(0,1,0,"Menu2")

        subMenu[0].setOnMenuItemClickListener {
            it.isChecked = true

            return@setOnMenuItemClickListener true
        }

        setCounterValueToMenuItem(subMenu.getItem(0),2)
    }

    private fun setMenuItemActionView(menuItem: MenuItem){
        menuItem.setActionView(R.layout.drawer_menu_with_counter)
    }

    private fun setCounterValueToMenuItem(menuItem: MenuItem,count: Int){
        val frameLayout: FrameLayout = menuItem.actionView as FrameLayout
        val textView = frameLayout.findViewById<TextView>(R.id.counter)

        textView.text = count.toString()
    }

Answer 1

So finally I figured out how to handle this situation.

In the menu items observer (in fact, these items are just a String name list), I call addExtraMenu function. The first menu item index starts from 0...N, therefore the submenu index has to be a big number, so that by chance it should not be the same. If the menuItems changed in runtime, you have to remove the old subMenu, and recreate it. I didn't want to handle the checked state, it wasn't necessary in my case.

 private fun addExtraMenu(types: List<IndustryType>) {
        val navView = binding.navView
        val menu = navView.menu
        val subMenuIndex = 999

        menu.findItem(subMenuIndex)?.let {
            menu.removeItem(it.itemId)
        }

        val subMenu = menu.addSubMenu(0, subMenuIndex, 0, R.string.drawer_menu_dynamic_group_label)

        types.forEachIndexed { _, industryType ->

            subMenu.add(0, industryType.indexOfMenu, industryType.indexOfMenu, industryType.name)

            setMenuItemActionView(subMenu[industryType.indexOfMenu])

            subMenu.getItem(industryType.indexOfMenu)?.setOnMenuItemClickListener {
                setDynamicMenuClickListener(industryType.oid)
            }
        }
    }

    private fun setDynamicMenuClickListener(industryTypeOid: String?): Boolean {
        val navController = findNavController(R.id.nav_host_fragment_content_main)

        binding.drawerLayout.close()

        val b = bundleOf(Pair("industryTypeOid", industryTypeOid))

        navController.navigate(R.id.nav_project_browser, b)

        return true
    }