Setting NavGraph programmatically

问题

In my activity layout, I have the following NavHostFragment:

<fragment
            android:id="@+id/my_nav_host_fragment"
            android:layout_height="match_parent"
            android:layout_width="match_parent"
            android:name="androidx.navigation.fragment.NavHostFragment"
            app:defaultNavHost="true"
            app:navGraph="@navigation/my_nav_graph" />

My question is how can I set the navGraph programmatically? How can I convert the my_nav_host_fragment view instance in a NavHostFragment instance?

回答1:

I found a solution:

//Setup the navGraph for this activity
val myNavHostFragment: NavHostFragment = my_nav_host_fragment as NavHostFragment
val inflater = myNavHostFragment.navController.navInflater
val graph = inflater.inflate(R.navigation.my_nav_graph)
myNavHostFragment.navController.graph = graph

Based on: Navigation Architecture Component- Passing argument data to the startDestination

回答2:

You can write in your Activity as follows.

findNavController(R.id.my_nav_host_fragment).setGraph(R.navigation.my_nav_graph)

来源：https://stackoverflow.com/questions/50898996/setting-navgraph-programmatically