Android Studio-禁用默认导航抽屉上的后退按钮

因此，我创建了默认的导航抽屉活动，并在底部添加了自己的按钮来手动更改片段

但是，我不希望这些按钮添加到后堆栈中，因为我希望导航菜单始终显示汉堡菜单而不是后退按钮。菜单我基本上希望在更改导航抽屉上的片段时禁用后退按钮和堆栈。我将如何实现这一点

这在onCreate中的导航活动中

        setContentView(R.layout.activity_navigation);
        Toolbar toolbar = findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        DrawerLayout drawer = findViewById(R.id.drawer_layout);
        NavigationView navigationView = findViewById(R.id.nav_view);
        // Passing each menu ID as a set of Ids because each
        // menu should be considered as top level destinations.
        mAppBarConfiguration = new AppBarConfiguration.Builder(
                R.id.nav_home, R.id.nav_projects,
                R.id.nav_tools, R.id.nav_share, R.id.nav_send)
                .setDrawerLayout(drawer)
                .build();
        this.navController = Navigation.findNavController(this, R.id.nav_host_fragment);
        NavigationUI.setupActionBarWithNavController(this, this.navController, mAppBarConfiguration);
        NavigationUI.setupWithNavController(navigationView, this.navController);

试试这些：

getSupportActionBar().setDisplayHomeAsUpEnabled(false); 
getSupportActionBar().setDisplayShowHomeEnabled(false);

---

使用NavController.OnNavigatedListener更新工具栏图标

val navController = Navigation.findNavController(this, R.id.fragment_main_navHost)
navController.addOnNavigatedListener(contoller, destination -> {
   if(destination.id == R.id.fragmentTwo){
          // update the toolbar here
}
    })