I'm having troubles with Up Arrow. So basically I have one activity(MainActivity) and two fragments (1. ListFragment 2.AddFragment). When I press up arrow from my AddFragment nothing happens, and I need to implement function that when I click that arrow it navigates me back to ListFragment.
My Activity:
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val navController = findNavController(R.id.navHostFragment)
setupActionBarWithNavController(navController)
}
}
This is my startDestination fragment:
class ListFragment : Fragment() {
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
// Inflate the layout for this fragment
val view = inflater.inflate(R.layout.fragment_list, container, false)
val addButton = view.findViewById<FloatingActionButton>(R.id.floatingActionButton)
addButton.setOnClickListener {
findNavController().navigate(R.id.navTo_addFragment)
}
return view
}
}
And this is my second fragment. So here is the problem, I can see the Up Arrow, but when I click it nothing happens, and I want to implement function that when I press up arrow that it navigates me back to ListFragment above.
class AddFragment : Fragment() {
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_add, container, false)
}
}
And here is my navigation graph:
<?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/my_nav"
app:startDestination="#id/listFragment">
<fragment
android:id="#+id/listFragment"
android:name="com.jovanovic.stefan.tododemo.ListFragment"
android:label="ToDo List"
tools:layout="#layout/fragment_list" >
<action
android:id="#+id/navTo_addFragment"
app:destination="#id/addFragment" />
</fragment>
<fragment
android:id="#+id/addFragment"
android:name="com.jovanovic.stefan.tododemo.AddFragment"
android:label="fragment_add"
tools:layout="#layout/fragment_add" >
<action
android:id="#+id/navTo_ListFragment"
app:destination="#id/listFragment"
app:popUpToInclusive="false" />
</fragment>
</navigation>
You need to setup NavigateUp handler on MainActivity
class MainActivity : AppCompatActivity() {
lateinit var navController: NavController
lateinit var appBarConfiguration: AppBarConfiguration
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
navController = findNavController(R.id.navHostFragment)
appBarConfiguration = AppBarConfiguration(navController.graph)
setupActionBarWithNavController(this, navController, appBarConfiguration)
}
override fun onSupportNavigateUp(): Boolean {
return navController.navigateUp()
|| super.onSupportNavigateUp()
}
}
Related
When I go to the main fragment from the login fragment for the first time and press the logout in the menu item in this fragment, I return to the login fragment again. However, when I go to the main fragment from the login fragment for the second time and press the logout button in the menu item again, I get this error. I couldn't understand what the problem is. Why is it throwing an error in the second loop?
** java.lang.IllegalStateException: Fragment MainFragment{632a8a3} (33a94b4d-9e85-4315-ae99-51e5edc7ddc2 id=0x7f08015e) did not return a View from onCreateView() or this was called before onCreateView().**
class LoginFragment : Fragment() {
private lateinit var binding : FragmentLoginBinding
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
auth = Firebase.auth
database = Firebase.database.reference
}
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
binding = FragmentLoginBinding.inflate(inflater,container,false)
return binding.root
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
binding.apply {
btnConfirm.setOnClickListener {
Navigation.findNavController(requireView()).navigate(R.id.action_loginFragment_to_mainFragment)
}
}
}
class MainFragment : Fragment() {
private lateinit var binding : FragmentMainBinding
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
}
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
binding = FragmentMainBinding.inflate(inflater, container, false)
return binding.root
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
val toolbar = binding.toolbar
(requireActivity() as AppCompatActivity).setSupportActionBar(toolbar)
requireActivity().addMenuProvider(object : MenuProvider {
override fun onCreateMenu(menu: Menu, menuInflater: MenuInflater) {
if(menu.size()==0){
menuInflater.inflate(R.menu.main_menu,menu)
}
}
override fun onMenuItemSelected(menuItem: MenuItem): Boolean {
return when (menuItem.itemId) {
R.id.logout ->{
Navigation.findNavController(requireView()).navigate(R.id.action_mainFragment_to_loginFragment)
true
}
else -> false
}
}
})
}
}
<?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_menu"
app:startDestination="#id/splashFragment">
<fragment
android:id="#+id/loginFragment"
android:name="com.yasinsenel.yapacaklarm.view.fragment.LoginRegisterFragment"
android:label="fragment_login"
tools:layout="#layout/fragment_login" >
<action
android:id="#+id/action_loginFragment_to_mainFragment"
app:destination="#id/mainFragment"
app:enterAnim="#anim/nav_default_enter_anim"
app:exitAnim="#anim/nav_default_exit_anim" />
</fragment>
<fragment
android:id="#+id/mainFragment"
android:name="com.yasinsenel.yapacaklarm.view.fragment.MainFragment"
android:label="fragment_main"
tools:layout="#layout/fragment_main" >
<action
android:id="#+id/action_mainFragment_to_loginFragment"
app:destination="#id/loginFragment" />
</navigation>
have yot tried setting _binding = null in OnDestroyView
maybe previous binding instance stills in memory
I have simple DialogWindow
XML:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="300dp"
android:layout_height="150dp"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:orientation="vertical">
<fragment
android:id="#+id/nav_host_fragment_activity_main"
android:name="androidx.navigation.fragment.NavHostFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:defaultNavHost="true"
app:navGraph="#navigation/navigation"/>
</LinearLayout>
Code:
class DialogWindowBuyingStock(context: Context, private val viewModel: MainViewModel, private val stock: Stock) : AppCompatDialog(context) {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
supportRequestWindowFeature(Window.FEATURE_NO_TITLE)
setContentView(R.layout.buy_stock_dialogwindow)
}
}
In which i have some fragments for example the Main one:
class MainFragment : Fragment() {
private var _binding: MainFragmentBinding? = null
private val binding get() = _binding!!
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View {
val homeViewModel =
ViewModelProvider(this)[MainFragmentViewModel::class.java]
_binding = MainFragmentBinding.inflate(inflater, container, false)
val root: View = binding.root
return root
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
main_buy_button.setOnClickListener {
Navigation.findNavController(view).navigate(R.id.action_mainFragment_to_buyFragment)
}
}
override fun onDestroyView() {
super.onDestroyView()
_binding = null
}
}
It works perfectly for the first time i start Dialog Window, but when i close it and start again, i got this llegalArgumentException: Binary XML file line #20: Duplicate id 0x7f080136, tag null, or parent id 0xffffffff with another fragment for androidx.navigation.fragment.NavHostFragment
How can i fix that?
I'm using Navigation Component with Kotlin, and have three main tabs in nav_dashboard - Explore, My Groups and Profile. When I start application the startDestination is nav_explore, but then I want to go from there to different screens eg. CreateGroupFragment/nav_create_group and from there I have button that I want to redirect me to nav_dashboard but with My Groups selected - I guess that then the startDestination needs to be nav_profile. But how I can I implement that?
Dashboard Fragment (it contains Fragment Container View in XML):
internal class DashboardFragment : Fragment() {
lateinit var navigator: DashboardNavigator
private var _binding: FragmentDashboardBinding? = null
private val binding
get() = _binding!!
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
_binding = FragmentDashboardBinding.inflate(layoutInflater, container, false)
return binding.root
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
initBottomNavigation()
}
private fun initBottomNavigation() {
with(binding.bottomNavigationView) {
setupWithNavController(getDashboardNestedNavController())
}
}
private fun getDashboardNestedNavController(): NavController {
val navHostFragment = childFragmentManager.findFragmentById(R.id.nav_host_container) as NavHostFragment
val navGraph = navHostFragment.navController.navInflater.inflate(R.navigation.nav_dashboard_menu)
navHostFragment.navController.addOnDestinationChangedListener { _, destination, bundle ->
when (destination.id) {
R.id.exploreFragment, R.id.myGroupsFragment, R.id.profileFragment -> setBottomNavVisibility(View.VISIBLE)
else -> setBottomNavVisibility(View.GONE)
}
}
return navHostFragment.navController
}
private fun setBottomNavVisibility(visibility: Int) {
binding.bottomNavigationView.visibility = visibility
}
}
nav_dashboard:
<?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"
android:id="#+id/nav_dashboard_menu"
app:startDestination="#id/nav_explore">
<include app:graph="#navigation/nav_explore" />
<include app:graph="#navigation/nav_my_groups" />
<include app:graph="#navigation/nav_profile" />
</navigation>
nav_create_group:
<?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_create_group"
app:startDestination="#id/createGroupFragment">
<include app:graph="#navigation/nav_create_group_map" />
<include app:graph="#navigation/nav_my_groups" />
<fragment
android:id="#+id/createGroupFragment"
android:name="com.wojciechkula.locals.presentation.creategroup.CreateGroupFragment"
android:label="#string/create_group_create_group"
tools:layout="#layout/fragment_create_group">
<action
android:id="#+id/openMap"
app:destination="#id/nav_create_group_map" />
<!-- Here I want another action to navigate to nav_dashboard with startDestination: nav_my_groups-->
</fragment>
</navigation>
First of all, you don't need to change the startDestination.
Secondly, why are you using multiple graphs? That usually makes things more complicated!
Anyway, you can just set the selected tab manually.
binding.bottomNavigationView.menu.findItem(R.id.tabId).isChecked = true
"tabId" is the id of the item in your bottom nav xml file.
This is my FragmentTwo fragment class code.
class FragmentTwo : Fragment() {
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?,
): View? {
// Inflate the layout for this fragment
val binding : FragmentTwoBinding = DataBindingUtil.inflate(inflater,R.layout.fragment_two, container, false)
var args = FragmentTwoArgs.fromBundle(arguments)
setHasOptionsMenu(true)
return binding.root
}
override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
super.onCreateOptionsMenu(menu, inflater)
inflater?.inflate(R.menu.overflow_menu,menu)
}
override fun onOptionsItemSelected(item: MenuItem): Boolean {
return NavigationUI.onNavDestinationSelected(item!!,findNavController())
|| super.onOptionsItemSelected(item)
}
}
This is my FragmentOne fragment class code:
class FragmentOne : Fragment() {
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
// Inflate the layout for this fragment
// return inflater.inflate(R.layout.fragment_one, container, false)
val binding: FragmentOneBinding =
DataBindingUtil.inflate(inflater, R.layout.fragment_one, container, false)
binding.clickable = this
return binding.root
}
fun onClicking() {
//Toast.makeText(activity, "You clicked me.", Toast.LENGTH_SHORT).show()
//findNavController().navigate(R.id.action_fragmentOne_to_fragmentTwo)
findNavController().navigate(FragmentOneDirections.actionFragmentOneToFragmentTwo())
}
}
And this is my Navigation xml code.
<?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/navigation"
app:startDestination="#id/fragmentOne">
<fragment
android:id="#+id/fragmentOne"
android:name="com.example.fragmentpractise1.FragmentOne"
android:label="fragment_one"
tools:layout="#layout/fragment_one" >
<action
android:id="#+id/action_fragmentOne_to_fragmentTwo"
app:destination="#id/fragmentTwo" />
<argument
android:name="numViews"
app:argType="integer"
android:defaultValue="18" />
</fragment>
<fragment
android:id="#+id/fragmentTwo"
android:name="com.example.fragmentpractise1.FragmentTwo"
android:label="fragment_two"
tools:layout="#layout/fragment_two" />
<fragment
android:id="#+id/aboutFragment"
android:name="com.example.fragmentpractise1.AboutFragment"
android:label="fragment_about"
tools:layout="#layout/fragment_about" />
</navigation>
Now I am getting an error in FragmentTwo class code as FragmentTwoArgs class is not generated while assigning it to args variable. I am using Nav safe args and defined argument value through Nav graph in FragmentOne.
Any help would be appreciated.
You're using wrong Fragment to declare the arguments. If you want FragmentTwo to have arguments you should use the fragment in the navigation xml:
<fragment
android:id="#+id/fragmentTwo"
android:name="com.example.fragmentpractise1.FragmentTwo"
android:label="fragment_two"
tools:layout="#layout/fragment_two">
<argument
android:name="numViews"
app:argType="integer"
android:defaultValue="18" />
</fragment>
You might also want to use the lazy delegate navArgs():
private val args: FragmentTwoArgs by navArgs()
Hi I have a strange problem. MainActivity has a framelayout and a main fragment EnterFragment.
EnterFragment has a framelayout and i'd like to see other 2 fragments. SignupFragment and LoginFragment.
When EnterFragment starts, it shows SignupFragment.java.. after MainActivity invoke a method of EnterFragment to change fragment to LoginFragment but app crash:
java.lang.IllegalStateException: Fragment EnterFragment{95bc7de (70f980b2-eff8-4e4c-a644-e95544b73584)} has not been attached yet.
at androidx.fragment.app.Fragment.getChildFragmentManager(Fragment.java:923)
Here the project: https://www.dropbox.com/s/qq1kl4qw688ipjr/example.zip?dl=0
Here the code:
//MainActivity
class MainActivity : AppCompatActivity() {
private var enterFragment: EnterFragment?=null
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
showEnter()
}
private fun showEnter() {
enterFragment= EnterFragment.newInstance()
this.replaceFragmentTransition(R.id.fragmentContainer, EnterFragment.newInstance(), EnterFragment.TAG )
var handler= Handler()
handler.postDelayed(Runnable {gotoLoginFromSignup() }, 8000)
}
private fun gotoLoginFromSignup() {
enterFragment?.gotoLogin()
}
}
//EnterFragment
class EnterFragment : Fragment() {
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
return inflater.inflate(R.layout.fragment_enrer, container, false)
}
override fun onActivityCreated(savedInstanceState: Bundle?) {
super.onActivityCreated(savedInstanceState)
this.replaceFragmentTransition(R.id.fmContainer, SignuFragment.newInstance(), SignuFragment.TAG )
}
fun gotoLogin(){
this.replaceFragmentTransition(R.id.fmContainer, LoginFragment.newInstance(), SignuFragment.TAG )
}
companion object {
val TAG: String="EnterFragment"
#JvmStatic
fun newInstance() = EnterFragment()
}
}
//SignupFragment
class SignuFragment : Fragment() {
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
return inflater.inflate(R.layout.fragment_signup, container, false)
}
companion object {
val TAG: String="SignuFragment"
#JvmStatic
fun newInstance() = SignuFragment()
}
}
//LoginFragment
class LoginFragment : Fragment() {
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
return inflater.inflate(R.layout.fragment_login, container, false)
}
companion object {
val TAG: String="LoginFragment"
#JvmStatic
fun newInstance() = LoginFragment()
}
}
//EXTENSIONS
fun FragmentActivity.replaceFragmentTransition(
container: Int,
fragment: Fragment?,
tag: String
) {
fragment?.let {
var transition = this.supportFragmentManager
.beginTransaction()
transition.replace(container, it, tag)
.commitNowAllowingStateLoss()
}
}
fun Fragment.replaceFragmentTransition(
container: Int,
fragment: Fragment?,
tag: String
) {
fragment?.let {
var transition = this.childFragmentManager
.beginTransaction()
transition.replace(container, it, tag)
.commitNowAllowingStateLoss()
}
}
//main activity layout
<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">
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/fragmentContainer"
android:layout_width="0dp"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
android:layout_height="0dp" />
</androidx.constraintlayout.widget.ConstraintLayout>
//enterFragment
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
tools:context=".EnterFragment">
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/fmContainer"
android:layout_width="0dp"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
android:layout_height="0dp" />
</androidx.constraintlayout.widget.ConstraintLayout>
Replace this
this.replaceFragment(R.id.fragmentContainer, FatherFragment.newInstance(), FatherFragment.TAG )
with
this.replaceFragment(R.id.fragmentContainer, fatherFragment!!, FatherFragment.TAG )
while transaction, you are passing different instance & calling openLogin() with another instance.
FatherFragment.newInstance() will give new instance.