Java - 单击菜单项打开片段

Question

我正在 android studio 中使用 id 在组中添加菜单。我遇到了菜单点击事件的问题，因为当我点击它时它不会做任何事情。

这是我尝试过的：

public boolean onOptionsItemSelected(MenuItem item) { 片段 newFragment = null; // 这是你要放入FrameLayout的片段 int id = item.getItemId();

    if (id == R.id.nav_group1) {
        newFragment = new FolderFragment();
    }

    // Let's put the new fragment into the FrameLayout
    // If you use the support action bar, use getSupportFragmentManager(), else getFragmentManager()
    FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
    transaction.replace(R.id.nav_host_fragment, newFragment); // R.id.fragment_container = FrameLayout ID
    transaction.commit();

    return true;
}

这是我用来添加菜单的：

NavigationView navigationView = findViewById(R.id.nav_view);
Menu menu = navigationView.getMenu();

try {
    JSONArray jsonArray = new JSONArray(folders);
    int id = 1;
    int order = 100;

    for (int i = 0; i < jsonArray.length(); i++) {
        String folder = jsonArray.getString(i);

        menu.add(R.id.nav_group1, id, order, folder)
            .setIcon(R.drawable.ic_baseline_folder_24);
        id++;
            order++;
    }
} catch (JSONException e) {
    e.printStackTrace();
}

mAppBarConfiguration = new AppBarConfiguration.Builder(
            R.id.nav_inbox, R.id.nav_important, R.id.nav_sent, R.id.nav_drafts, R.id.nav_spam, R.id.nav_trash, R.id.nav_group1, R.id.nav_create_new_folder, R.id.nav_contact)
            .setDrawerLayout(drawer)
            .build();
NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment);
NavigationUI.setupActionBarWithNavController(this, navController, mAppBarConfiguration);
NavigationUI.setupWithNavController(navigationView, navController);

我想要实现的是当我点击菜单时，我想打开 nav_group 下的片段。

你能否给我举个例子，当我使用 java 添加菜单时，我如何点击菜单打开片段？