我使用的是bottom navigation。
在切换的屏幕中，还有一个打开dialog fragment的功能。
我还使用了导航功能。
这是因为，一旦dialog完成，data就必须传送到打开对话框的屏幕。
我使用了safe args。
但是我得到了和标题一样的错误。
我知道错误在哪里，但我不知道它发生的确切原因。
根据在Stack Overflow上的搜索，有人遇到过和我一样的问题，但这似乎不是一个确切的解决方案，因为情况不同。

导航图

<navigation xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/nav_graph"
    app:startDestination="@id/calendar">
    <fragment
        android:id="@+id/calendar"
        android:name="com.example.writeweight.fragment.CalendarFragment"
        android:label="fragment_calendar"
        tools:layout="@layout/fragment_calendar" >
    </fragment>
    <fragment
        android:id="@+id/list"
        android:name="com.example.writeweight.fragment.WorkoutListFragment"
        android:label="fragment_workout_list"
        tools:layout="@layout/fragment_workout_list" />
    <fragment
        android:id="@+id/write"
        android:name="com.example.writeweight.fragment.WritingRoutineFragment"
        android:label="WritingRoutineFragment"
        tools:layout="@layout/fragment_writing_routine">
        <action
            android:id="@+id/action_write_to_bodyPartDialog"
            app:destination="@id/bodyPartDialog" />
        <argument
            android:name="title"
            app:argType="string"
            android:defaultValue="Write" />
    </fragment>
    <dialog
        android:id="@+id/bodyPartDialog"
        android:name="com.example.writeweight.fragment.BodyPartDialogFragment"
        android:label="BodyPartDialogFragment"
        tools:layout="@layout/fragment_body_part_dialog">
        <action
            android:id="@+id/action_bodyPartDialog_to_write"
            app:destination="@id/write">
        </action>
    </dialog>
</navigation>

主要活动

class MainActivity : AppCompatActivity() {
    private lateinit var bottomNav: BottomNavigationView
    private lateinit var navController: NavController

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        bottomNav = findViewById(R.id.bottom_nav)
        val navHostFragment = supportFragmentManager.findFragmentById(R.id.nav_host_container) as NavHostFragment
        navController = navHostFragment.navController
        bottomNav.setupWithNavController(navController)
    }
}

对话片段

class BodyPartDialogFragment : DialogFragment() {
    private lateinit var ll: LinearLayout
    private lateinit var startBtn: Button
    private lateinit var title: String

    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
        val view: View = inflater.inflate(R.layout.fragment_body_part_dialog, container, false)

        initView(view)
        setLayout()

        startBtn?.setOnClickListener { v ->
            title = BodyPartCustomView.getTitle()
            val action = BodyPartDialogFragmentDirections.actionBodyPartDialogToWrite(title)
            findNavController()?.navigate(action) // Possibly the location of the error.
            dismiss()
            
        }
        return view
    }

    private fun initView(view: View) {
        ll = view.findViewById(R.id.ll_body_part)
        startBtn = view.findViewById(R.id.start)
    }

    private fun setLayout() {
        ll?.apply { clipToOutline = true }
    }

    override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
        val dialog:Dialog = super.onCreateDialog(savedInstanceState)
        dialog.window?.setBackgroundDrawable(ColorDrawable(Color.TRANSPARENT))
        dialog.setCanceledOnTouchOutside(false)
        return dialog
    }

    override fun onDismiss(dialog: DialogInterface) {
        Toast.makeText(context, "CHECK", Toast.LENGTH_SHORT).show()
    }
}