根据this issue，当使用FragmentContainerView时，需要使用findFragmentById()而不是在onCreate()中使用findNavController()来查找NavController：

val navHostFragment = supportFragmentManager.findFragmentById(R.id.nav_host_fragment) as NavHostFragment
val navController = navHostFragment.navController

这是因为findNavController(R.id.nav_host_fragment)依赖于已经创建的Fragment视图，而使用FragmentContainerView时则不是这样（因为它使用了一个FragmentTransaction来添加NavHostFragment）。
如果您使用的是Fragment 1.4.0或更高版本以及View Binding，则可以通过使用getFragment()方法来大大简化此过程：

val navController = binding.container.getFragment<NavHostFragment>().navController

替换此行：

NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment);

与

NavController navController = getNavController();

其中getNavController()如下所示：

// workaround for https://issuetracker.google.com/issues/142847973
    @NonNull
    private NavController getNavController() {
        Fragment fragment = getSupportFragmentManager().findFragmentById(R.id.nav_host_fragment);
        if (!(fragment instanceof NavHostFragment)) {
            throw new IllegalStateException("Activity " + this
                    + " does not have a NavHostFragment");
        }
        return ((NavHostFragment) fragment).getNavController();
    }

除了公认的答案之外，还有一个可以使用的小捷径：

supportFragmentManager.findFragmentById(R.id.navHostMain)?.findNavController()

此致

添加到您的build.gradle（模块：App）这一行

implementation "androidx.navigation:navigation-fragment-ktx:2.3.2"

并在活动中使用

val navController = supportFragmentManager.findFragmentById(R.id.your_id_nav_host_fragment)
            ?.findNavController()

和碎片

val navController = findNavController()

我用扩展解决了我的问题：

fun FragmentActivity.findFragmentContainerNavController(@IdRes host: Int):NavController {
    try {
        val navHostFragment = supportFragmentManager.findFragmentById(host) as NavHostFragment
        return navHostFragment.findNavController()
    } catch (e: Exception) {
        throw IllegalStateException("Activity $this does not have a NavController set on $host")
    }
}

使用简单的<fragment>标记，而不是<androidx.fragment.app.FragmentContainerView>

@friederbluemle的答案还有一个更简单的方法，Assert检查就足够了。

NavHostFragment navHostFragment 
    = (NavHostFragment) getSupportFragmentManager().findFragmentById(R.id.nav_host_fragment);
assert navHostFragment != null : "navHostFragment not found";
NavController navController = navHostFragment.getNavController();

答案很简单-

val navHostFragment = supportFragmentManager.findFragmentById(R.id.fragmentContainerView)

作为导航主机片段

val navController = navHostFragment.navControllermenus.setupWithNavController(navController)

我已经将<androidx.fragment.app.FragmentContainerView>更改为<fragment>，它对我很有效。