I have the following:
class SettingsFragment : Fragment() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
}
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_settings, container, false)
val auth = FirebaseAuth.getInstance()
signOutButton.setOnClickListener{
Log.i("TAG", "logout tapped")
auth.signOut()
startActivity(Intent(activity,LoginActivity::class.java))
}
}
}
The view loads, but when I tap the button to log the user out, I dont see a print out of the log and nor does the user logout and the view doesn't switch to the loginActivity().
My button:
<Button
android:id="#+id/signOutButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Sign out" />
As you have already returned the view the rest of the lines will never be called. It's unreachable. return be at the end of the function. Also, you will want to set the click listener after the view is created(onViewCreated) else you will get a NullPointerException.
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_settings, container, false)
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
val auth = FirebaseAuth.getInstance()
signOutButton.setOnClickListener{
Log.i("TAG", "logout tapped")
auth.signOut()
startActivity(Intent(activity,LoginActivity::class.java))
}
}
override the onViewCreated() function and write down your signout code there, Also initialize the signOutButton.
Related
I know this question has been asked many times but just wanted to have some more clarity.
So I wanted to create a simple fragment with a button that should change the fragment when clicked - very simple and basic one.
hence I create a function, and called it on onCreateView. Nothing happeded.
Then I created onViewCreated after onCreateView and called the same function in it.
It Worked.
My Question is What exactly made it work ?
here is the code
class homeFragment : Fragment() {
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_home, container, false)
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
hello()
}
fun hello()
{
val button = view?.findViewById<Button>(R.id.button_login)
button?.setOnClickListener{
val action = homeFragmentDirections.actionHomeFragmentToLoginFragment()
findNavController().navigate(action)
Toast.makeText(context,"wao",Toast.LENGTH_LONG).show()
}
}
}
As per your comments, you did something like this:
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
return inflater.inflate(R.layout.fragment_home, container, false)
hello() // the method has already returned a View, so this call is never reached.
}
So, when you call hello() in onCreateView after the return statement,
the method has no effect because of the return statement.
Since onViewCreated is called after the onCreateView,
the underlying View is no more null in your hello function.
If you still want to use onCreateView, you can do something like this:
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
val fragmentView = inflater.inflate(R.layout.fragment_home, container, false)
hello(fragmentView)
return fragmentView
}
fun hello(buttonHolderView: View?) {
val button = buttonHolderView?.findViewById<Button>(R.id.button_login)
button?.setOnClickListener {
val action = homeFragmentDirections.actionHomeFragmentToLoginFragment()
findNavController().navigate(action)
Toast.makeText(context, "wao", Toast.LENGTH_LONG).show()
}
}
You need to inflate the view before calling the function:
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
val fragmentHome = inflater.inflate(R.layout.fragment_home, container, false)
hello(fragmentHome)
return fragmentHome;
}
Change your hello function:
fun hello(view: View)
{
....
In my application i want use fragment and i want show Toast message just when users see this fragment show message.
I write below codes but when show fragment not show me any Toast!
In java i haven't any issue and show Toast, but when use kotlin not show Toast!
My codes:
class TestFragment : Fragment() {
private val title by lazy { arguments?.getString("title") ?: "" }
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?): View? {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_test, container, false)
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
testFragText.text = title
}
override fun setUserVisibleHint(isVisibleToUser: Boolean) {
super.setUserVisibleHint(isVisibleToUser)
if (isVisibleToUser){Toast.makeText(context, "Show", Toast.LENGTH_SHORT).show()}
}
}
How can i fix it?
I'm trying to catch the onClick event from a button inside a fragment but it's not working.
Any tip?
I have this main activity and I call the fragment throught a bottomNavigation.
MainActivity.kt:
class MainActivity : FragmentActivity() {
private val mOnNavigationItemSelectedListener = BottomNavigationView.OnNavigationItemSelectedListener { item ->
when (item.itemId) {
R.id.navigation_home -> {
showFragmentSetup()
return#OnNavigationItemSelectedListener true
}
}
false
}
fun showFragmentSetup(){
val setupFragment = SetupFragment()
val manager = supportFragmentManager
val transaction = manager.beginTransaction()
transaction.replace(R.id.setupFragment, setupFragment)
transaction.addToBackStack(null)
transaction.commit()
}
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
navigation.setOnNavigationItemSelectedListener(mOnNavigationItemSelectedListener)
}
}
The activity_main.xml is the container of the linearLayout which will cointain the fragment.
activity_main.xml
<LinearLayout
android:id="#+id/setupFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="vertical"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
/>
My fragment is simple it just have a button and i want to catch the onClickEvent from this button
class SetupFragment : Fragment(){
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?): View? {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_setup, container, false)
val view: View = inflater!!.inflate(R.layout.fragment_setup, container, false)
btnSetup.setOnClickListener { view ->
Log.d("btnSetup", "Selected")
}
// Return the fragment view/layout
return view
}
companion object {
fun newInstance(): SetupFragment {
return SetupFragment()
}
}
}
You're returning before you can setup the listener here:
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?): View? {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_setup, container, false)
val view: View = inflater!!.inflate(R.layout.fragment_setup, container, false)
btnSetup.setOnClickListener { view ->
Log.d("btnSetup", "Selected")
}
// Return the fragment view/layout
return view
}
Try like this:
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?): View? {
val view: View = inflater!!.inflate(R.layout.fragment_setup, container, false)
view.btnSetup.setOnClickListener { view ->
Log.d("btnSetup", "Selected")
}
// Return the fragment view/layout
return view
}
I think you should use "onViewCreated" function in your "SetupFragment"
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
btnSetup.setOnClickListener { view ->
Log.d("btnSetup", "Selected")
}
}
You're not providing that button a view
lateinit var mView: View
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
mView=inflater.inflate(R.layout.product_list,container,false)
mView.addProduct.setOnClickListener {
val intent=Intent(activity,ProductAddActivity::class.java)
startActivity(intent)
}
return mView
}
This is how to go about in viewBinding after setting your View.Oclicklisterner interface in your fragment
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View {
_binding = FragmentMenuBinding.inflate(inflater, container, false)
val root: View = binding.root
_binding?.tvPlattersChip?.setOnClickListener(this)
_binding?.tvPizzaChip?.setOnClickListener(this)
return root
}
I have a simply Activity. In this activity I want start a fragment. But the Fragment doesn't start.
This is my Activity
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
//start Homefragment
startHomeFragment()
}
/**
* Create Homefragment
*/
private fun startHomeFragment() {
val homeFragment = fragmentManager.findFragmentByTag(statics.TAG) ?: HomeFragment()
fragmentManager.beginTransaction()
.replace(R.id.container, homeFragment, statics.TAG)
.commit()
}
And this is my Fragment
class HomeFragment : Fragment() {
object statics {
#JvmField val TAG = "Homefragment"
}
override fun onCreateView(inflater: LayoutInflater?, container: ViewGroup?, savedInstanceState: Bundle?): View? {
return super.onCreateView(inflater, container, savedInstanceState)
inflater?.inflate(R.layout.fragment_home, container)
background_home.setBackgroundResource(R.drawable.gc_bg_home)
All the code after
return super.onCreateView(inflater, container, savedInstanceState)
is unreachable. Just read IDE warnings.
Also, layout becomes attached only if you returned it from onCreateView, i. e. return inflater.inflate(...).
In Kotlin the onCreateView should be on this way
override fun onCreateView(inflater: LayoutInflater?, container: ViewGroup?,
savedInstanceState: Bundle?): View? {
return inflater!!.inflate(R.layout.input_field_frag, container, false)
}
If you want to add somthing inside you fragment you can use onViewCreated method and do whatever you want here
override fun onViewCreated(view: View?, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
//Here u can call function of add listners to button...
})
}
Like this you gonna create a safe propriate code
Solved:
class HomeFragment : Fragment() {
object statics {
#JvmField val TAG = "Homefragment"
}
override fun onCreateView(inflater: LayoutInflater?, container: ViewGroup?, savedInstanceState: Bundle?): View? {
Toast.makeText(activity, "HomeFragment", Toast.LENGTH_SHORT).show()
return inflater?.inflate(R.layout.fragment_home, container, false)
}
}
class HomeFragment : Fragment() {
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?): View? {
// Inflate the layout for this fragment
val v = inflater.inflate(R.layout.fragment_home, container, false)
val fab = v.findViewById(R.id.fab) as FloatingActionButton
fab.setOnClickListener {
val blankFragment = BlankFragment()
val manager = childFragmentManager
manager.beginTransaction().replace(R.id.frame_container, blankFragment, blankFragment.tag).commit()
// System.out.println("You have reached the floating action button")
}
return v
}
}
Getting a no view found error. I may have issues with the R.id.frame_content but Kotlin doesn't immediately identify all id values...
This may not be the best way and I apologize for the horrible formatting I does this while answer out on my phone and it's hard to get it perfect. Anyways In the activity that holds your fragments, such as MainActivity.kt add...
supportFragmentManager.beginTransaction.add(R.id.fragment_home, HomeFragment.newInstance, "HomeFragment").commit()
In your HomeFragment.kt change the following.
class HomeFragment: Fragment(){
companion object {
fun newInstance(): HomeFragment{
return HomeFragment() }
fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
val view: View = inflater!!.inflate(R.layout.fragment_home, container, false)
val activity = activity
return view
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
val clickListener = View.OnClickListener { view ->
when (view.getId()) {
R.id.fab -> NextFragment()
}
}
fab.setOnClickListener(clickListener)
}
NextFragment(){
val fragManager = activity?.supportFragmentManager
fragManager?.beginTransaction()?.replace(R.id.frame_container, BlankFragment.newInstance(), "blankFragment")?.commit()
}
Make sure you make the same changes to BlankFragment.kt
class BlankFragment: Fragment(){
companion object {
fun newInstance(): BlankFragment{
return BlankFragment() }
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
val view: View = inflater!!.inflate(R.layout.fragment_blank, container, false)
val activity = activity
return view
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
//Do some stuff with your views in BlankFragment here
}
}