Develop Reference

Trying to sent data from activity to fragment

In Main
override fun pastDada(name: String) {
val bundle = Bundle()
bundle.putString("USER_NAME", "DDDDDDDD")
val transction = this.supportFragmentManager.beginTransaction()
val profileFragmant = fragment_profile()
profileFragmant.arguments = bundle
transction.replace(R.id.container,profileFragmant)
}
In Frafment:
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
// Inflate the layout for this fragment
var view = inflater.inflate(R.layout.fragment_profile2, container, false)
name = arguments?.getString("USER_NAME")
Log.e("name", arguments?.getString("USER_NAME").toString())
Log.e("name", name.toString())
view.tv_name.text = name
return view
}
the result of Log.e("name", name.toString()) is always null and I dont know why
maby its becuse my arguments is empty?
and if it is,how am I supose to slove it?
Thanks

change your code like this
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
// Inflate the layout for this fragment
var view = inflater.inflate(R.layout.fragment_profile2, container, false)
val bundle = arguments
val name = bundle!!.getString("USER_NAME")
Log.e("name", name.toString())
view.tv_name.text = name
return view
}

Difference between onCreateView and onViewCreated in Fragment - Kotlin

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)
{
....

How to return multiple values VIEW in Kotlin?

I was trying to change ImageView in one Fragment from another Fragment. But since this cannot be done without container, I have to create another view value with the inflater method. Then I need to return these view values with the inflater methods. How do I return two views?
code is written in a fragment:
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
val view = inflater.inflate(R.layout.firstfragment, container, false)
val view2 = inflater.inflate(R.layout.secondfragment, container, false)
val imgPF: ImageView = view2.findViewById(R.id.imageView)
imgPF.setImageResource(R.drawable.image_29)
view.ButtonFromFirstFragment.setOnClickListener{
//Unimportant code
}
setHasOptionsMenu(true)
return view //Approximately here i need to return two views, but how?
//And can it be done somehow differently?
}

Basically you should not have 2 fragments within a fragment. Please double check that you are not confusing fragments with views.
If you want to have those 2 fragments in an activity and you are showing both of your fragments at the same time then you should have 2 separate fragments:
Fragment A:
(...)
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
val view = inflater.inflate(R.layout.firstfragment, container, false)
view.ButtonFromFirstFragment.setOnClickListener{
//Unimportant code
}
return view
}
(...)
Fragment B:
(...)
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
val view = inflater.inflate(R.layout.secondfragment, container, false)
val imgPF: ImageView = view.findViewById(R.id.imageView)
imgPF.setImageResource(R.drawable.image_29)
return view
}

Getting error findViewById when initiate recyclerview in a fragment

I have tested this code in another project where I didn't use fragment and wrote it in MainActivity.kt, it works. But a problem comes when I make another project using fragment so I write it in a new class (HerbalFragment.kt). It's getting error in "findViewById" for initiate Recyclerview and also getting error in "this". Here is my code (HerbalFragment.kt)
import android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.fragment.app.Fragment
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.recyclerview.widget.RecyclerView
/**
* A simple [Fragment] subclass.
*/
class HerbalFragment : Fragment() {
private lateinit var rvHerbal: RecyclerView
private var list: ArrayList<Herbal> = arrayListOf()
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
// Inflate the layout for this fragment
super.onViewCreated(view, savedInstanceState)
return inflater.inflate(R.layout.fragment_herbal, container, false)
rvHerbal = findViewById(R.id.rv_herbal)
rvHerbal.setHasFixedSize(true)
list.addAll(HerbalData.listData)
showRecyclerList()
}
private fun showRecyclerList() {
rvHerbal.layoutManager = LinearLayoutManager(this)
val listHerbalAdapter = ListHerbalAdapter(list)
rvHerbal.adapter = listHerbalAdapter
}
}[![enter image description here][1]][1]
Help me please, thanks before

As far as i have noticed your code is unreachable,
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
// Inflate the layout for this fragment
super.onViewCreated(view, savedInstanceState)
return inflater.inflate(R.layout.fragment_herbal, container, false)
// unreachable code you are already return the view so below code will never execute
rvHerbal = findViewById(R.id.rv_herbal)
rvHerbal.setHasFixedSize(true)
list.addAll(HerbalData.listData)
showRecyclerList()
}
To fix this issue you need to change your code as i have suggested.
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
return inflater.inflate(R.layout.fragment_herbal, container, false)
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
// do what ever you want here like find view ids and etc...
rvHerbal = findViewById(R.id.rv_herbal)
rvHerbal.setHasFixedSize(true)
list.addAll(HerbalData.listData)
showRecyclerList()
}
}
private fun showRecyclerList() {
rvHerbal.layoutManager = LinearLayoutManager(activity!!)
val listHerbalAdapter = ListHerbalAdapter(list)
rvHerbal.adapter = listHerbalAdapter
}

You do not have to find view if you use the kotlin data binding by this easy method
add import to this (fragment_herbal is your xml layout view file name)
import kotlinx.android.synthetic.main.fragment_herbal.*
then
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?): View? {
return inflater.inflate(R.layout.fragment_herbal, container, false)
}
then use your view item without findviewbyid
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
rvHerbal.setHasFixedSize(true)
list.addAll(HerbalData.listData)
showRecyclerList()
}

How do I correctly use Kotlin to call a blank fragment from the Home fragment?

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
}
}