android - FragmentContainerView 作为 NavHostFragment

Question

好像使用 FragmentContainerView不能开箱即用？

<androidx.fragment.app.FragmentContainerView
        class="androidx.navigation.fragment.NavHostFragment"
        android:id="@+id/fragment_nav_host"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:defaultNavHost="true"
        app:navGraph="@navigation/nav_app" />

这是我使用 fragment-ktx:1.2.0-rc01 的代码我总是遇到这个错误:

Caused by: java.lang.IllegalStateException: Activity ...MainActivity@797467d does not have a NavController set on 2131296504

只需使用 <fragment>工作和 AFAIK，它应该被替换为 FragmentContainerView .

我是否遗漏了什么或者有人可以使用 FragmentContainerView作为 NavHostFragment ?

非常感谢!

Answer 1

由于此错误报告:
https://issuetracker.google.com/issues/142847973
这是唯一的方法(目前):

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

( java ):

NavHostFragment navHostFragment =
    (NavHostFragment) getSupportFragmentManager()
        .findFragmentById(R.id.my_nav_host_fragment);
NavController navController = navHostFragment.getNavController();