通过使用 FragmentContainerView 标签使用带有底部导航栏的导航组件

Question

我已经看过这个问题：关于这个问题。但是我仍然无法解决问题。它永远不会打开其他片段。我想可能是因为视图绑定，但我尝试在不使用视图绑定的情况下再次执行此操作。还是打不开。

MainActivity.kt

    class MainActivity : AppCompatActivity() {

    private lateinit var binding: ActivityMainBinding

    private lateinit var navController: NavController
    private lateinit var navHostFragment: NavHostFragment

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityMainBinding.inflate(layoutInflater)
        val view = binding.root
        setContentView(view)

        val navHostFragment =
            supportFragmentManager.findFragmentById(R.id.main_nav_host_fragment) as NavHostFragment
        navController = navHostFragment.navController
        binding.bottomNavigationView.setupWithNavController(navController)
        
    }

    override fun onOptionsItemSelected(item: MenuItem): Boolean {
        when (item.itemId) {
            R.id.home -> {
                navHostFragment.navController.popBackStack()
                return true
            }
        }
        return super.onOptionsItemSelected(item)
    }
}

activity_main.xml

    <?xml version="1.0" encoding="utf-8"?>
    <androidx.constraintlayout.widget.ConstraintLayout 
    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:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MainActivity">

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

    <com.google.android.material.bottomnavigation.BottomNavigationView
        android:id="@+id/bottomNavigationView"
        android:layout_width="match_parent"
        android:layout_height="56dp"
        app:menu="@menu/menu"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.5"
        app:layout_constraintStart_toStartOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

nav_graph_main

<?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_main"
    app:startDestination="@id/fragmentLibrary">

    <fragment
        android:id="@+id/fragmentLibrary"
        android:name="com.project.biosec.FragmentLibrary"
        android:label="fragment_library"
        tools:layout="@layout/fragment_library" />
    <fragment
        android:id="@+id/fragmentTransaction"
        android:name="com.project.biosec.FragmentTransaction"
        android:label="fragment_transaction"
        tools:layout="@layout/fragment_transaction" />
    <fragment
        android:id="@+id/fragmentAccount"
        android:name="com.project.biosec.FragmentAccount"
        android:label="fragment_account"
        tools:layout="@layout/fragment_account" >
        <action
            android:id="@+id/action_fragmentAccount_to_changeSignatureFragment"
            app:destination="@id/changeSignatureFragment" />
        <action
            android:id="@+id/action_fragmentAccount_to_securityFragment"
            app:destination="@id/securityFragment" />
        <action
            android:id="@+id/action_fragmentAccount_to_helpFragment"
            app:destination="@id/helpFragment" />
        <action
            android:id="@+id/action_fragmentAccount_to_termsFragment"
            app:destination="@id/termsFragment" />
    </fragment>
    <fragment
        android:id="@+id/changeSignatureFragment"
        android:name="com.project.biosec.ChangeSignatureFragment"
        android:label="fragment_change_signature"
        tools:layout="@layout/fragment_change_signature" />
    <fragment
        android:id="@+id/securityFragment"
        android:name="com.project.biosec.SecurityFragment"
        android:label="fragment_security"
        tools:layout="@layout/fragment_security" />
    <fragment
        android:id="@+id/helpFragment"
        android:name="com.project.biosec.HelpFragment"
        android:label="fragment_help"
        tools:layout="@layout/fragment_help" />
    <fragment
        android:id="@+id/termsFragment"
        android:name="com.project.biosec.TermsFragment"
        android:label="fragment_terms"
        tools:layout="@layout/fragment_terms" />
</navigation>

menu.xml

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">

    <item
        android:id="@+id/feed_fragment"
        android:icon="@drawable/ic_library"
        android:title="@string/library" />

    <item
        android:id="@+id/messages_fragment"
        android:icon="@drawable/ic_assignment"
        android:title="@string/transactions" />

    <item
        android:id="@+id/profile_fragment"
        android:icon="@drawable/ic_account"
        android:title="@string/account" />
</menu>

Answer 1

根据 Setting up bottom navigation guide:

Note: Setting up bottom navigation requires that you also set up your navigation graph and menu xml as described in Tie destinations to menu items.

该部分明确指出导航图 XML 文件中目的地的 android:id 需要与菜单 XML 中菜单项的 android:id 相匹配文件。

在您的情况下，您的导航 XML 使用 android:id="@+id/fragmentLibrary"、android:id="@+id/fragmentTransaction" 和 android:id="@+id/fragmentAccount"，因此您的菜单项应更改为使用这些相同的 ID。

通过使用 FragmentContainerView 标签使用带有底部导航栏的导航组件

Using navigation component with bottom navigation bar by using FragmentContainerView tag

android

kotlin

android-studio

android-architecture-navigation