android - 通过使用 FragmentContainerView 标签使用带有底部导航栏的导航组件
问题描述
我已经看过这个问题：FragmentContainerView using findNavController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这样做。它仍然没有打开。
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>
菜单.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>