Android：如何在不替换当前片段的情况下用导航图打开片段

如何解决Android：如何在不替换当前片段的情况下用导航图打开片段

我想知道是否有一种方法可以在屏幕上添加另一个片段，而不用导航图替换旧片段。

我要这样做是因为新的片段只是为了检查一些细节才打开一点，并且当用户返回到上一个片段时，我希望它们位于他们离开的同一位置。

我已经阅读了一遍，但是在没有替换原始书的情况下我找不到找到它的书。我试图将其添加到nav_graph_fragment中，我尝试在CurrentFragment部分的newFrag（）函数中执行此操作，但这不起作用。

主要活动

class MainActivity : AppCompatActivity() {

    private lateinit var toolbar: Toolbar
    private val navController by lazy {
        (supportFragmentManager.findFragmentById(R.id.nav_host_fragment) as NavHostFragment).navController
    }
    private lateinit var appBarConfiguration: AppBarConfiguration

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.main_activity)
        toolbar = findViewById(R.id.mainToolBar)
        setSupportActionBar(toolbar)
        appBarConfiguration = AppBarConfiguration(navController.graph,null)
        setupActionBarWithNavController(navController,appBarConfiguration)
    }

    override fun onCreateOptionsMenu(menu: Menu?): Boolean {
        val inflater: MenuInflater = menuInflater
        inflater.inflate(R.menu.main_menu_bar,menu)
        return true
    }

    override fun onSupportNavigateUp(): Boolean {
        return navController.navigateUp(appBarConfiguration) || super.onSupportNavigateUp()
    }

    override fun onOptionsItemSelected(item: MenuItem): Boolean {
        val navController = findNavController(R.id.nav_host_fragment)
        if (item.itemId == navController.currentDestination?.id)
            return true
        return item.onNavDestinationSelected(navController) || super.onOptionsItemSelected(item)
    }
}

主要活动xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".activity.MainActivity">

    <include
        layout="@layout/appbar"
        android:id="@+id/mainToolBar"/>

    <androidx.fragment.app.FragmentContainerView
        android:id="@+id/nav_host_fragment"
        android:name="androidx.navigation.fragment.NavHostFragment"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@id/mainToolBar"
        app:layout_constraintBottom_toBottomOf="parent"
        app:defaultNavHost="true"
        app:navGraph="@navigation/nav_graph" />

</androidx.constraintlayout.widget.ConstraintLayout>

CurrentFragment

class CurrentFragment : Fragment() {

    private lateinit var currentFragmentViewModel: CurrentFragmentViewModel
    private lateinit var binding: CurrentFragmentBinding
    private lateinit var recyclerView: RecyclerView

    override fun onCreateView(inflater: LayoutInflater,container: ViewGroup?,savedInstanceState: Bundle?): View? {

        binding = DataBindingUtil.inflate(inflater,R.layout.current_fragment,container,false)
        currentFragmentViewModel = ViewModelProvider(this).get(CurrentFragmentViewModel::class.java)
        binding.lifecycleOwner = this
        binding.viewmodel = currentFragmentViewModel

        binding.accountButton.setOnClickListener {
            Log.d("TEST","button clicked")
            newFrag()
        }

        return binding.root
    }


    // Here is where I am trying to open the new fragment
    private fun newFrag() {
        val newFrag = Fragment()
        val transaction: FragmentTransaction = parentFragmentManager.beginTransaction()
        transaction.hide(this)
        transaction.add(R.id.nav_host_fragment,newFrag).commit()

    }

}

导航图

<?xml version="1.0" encoding="utf-8"?>
<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/mainFragment">

    <fragment
        android:id="@+id/mainFragment"
        android:name="com.example.app.ui.main.MainFragment"
        android:label="MainFragment">
        <action
            android:id="@+id/action_mainFragment_to_currentFragment"
            app:destination="@id/currentFragment" />
    </fragment>
    <fragment
        android:id="@+id/currentFragment"
        android:name="com.example.app.ui.search.CurrentFragment"
        android:label="currentFragment" >
        
    </fragment>