如何在android中的NavigationView动态中添加菜单和子菜单

Question

我想在幻灯片导航中添加自定义菜单，菜单图标以及子菜单动态。下面的代码添加菜单成功但是当幻灯片导航出现时子菜单显示以及无法在菜单中添加图标所以请帮助我隐藏子菜单并仅显示带图标的菜单，当我点击菜单时，只显示其子菜单。

    public class MainActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener {

    private Toolbar toolbar;
    private DrawerLayout drawer;
    private NavigationView navigationView;

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        getId();

        ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
                this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
        drawer.setDrawerListener(toggle);
        toggle.syncState();


        navigationView.setNavigationItemSelectedListener(this);

        // Add menu dynamically
        Menu m = navigationView.getMenu();
        SubMenu topChannelMenu = m.addSubMenu("Top Channels");

        // Add submenu.
        topChannelMenu.add("Foo");
        topChannelMenu.add("Bar");
        topChannelMenu.add("Baz");

        topChannelMenu = m.addSubMenu("Top Channels2");
        topChannelMenu.add("Foo2");
        topChannelMenu.add("Bar2");
        topChannelMenu.add("Baz2");


        MenuItem mi = m.getItem(m.size()-1);
        mi.setTitle(mi.getTitle());
    }

    private void getId()
    {
        toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        navigationView = (NavigationView) findViewById(R.id.nav_view);
        drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    }

    @Override
    public void onBackPressed()
    {
        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        if (drawer.isDrawerOpen(GravityCompat.START))
        {
            drawer.closeDrawer(GravityCompat.START);
        } else
        {
            super.onBackPressed();
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu)
    {
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item)
    {
        int id = item.getItemId();

        if (id == R.id.action_settings)
        {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

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

        if (id == R.id.nav_camera)
        {
            // Handle the camera action
        } else if (id == R.id.nav_gallery)
        {

        } else if (id == R.id.nav_slideshow)
        {

        } else if (id == R.id.nav_manage)
        {

        } else if (id == R.id.nav_share)
        {

        } else if (id == R.id.nav_send)
        {

        }

        drawer.closeDrawer(GravityCompat.START);
        return true;
    }