在 kotlin 中打开另一个片段

Question

I'm totally desesperate. I try to open/replace fragment from one to another and only docs I can find is from an Activity or only in Java (with the getFragmentManager() method, seems to not exist in Kotlin).

supportFragmentManager is only available inside an Activity, and I'm using a fragment and adapter.

Could you please help me?

I think it's unless to show my code because it's just give nothing, only errors

None of the answers worked for me. I tried something else and create an interface :

interface AdapterCallbackAlbum {
fun onClickItem(album: Album)}

And implement this in my first fragment

class ListAlbumsFragment : Fragment(), AdapterCallbackAlbum {
  override fun onClickItem(album: Album) {
  val fragment = ListTracksFragment.newInstance()
  val transaction = childFragmentManager.beginTransaction()
  transaction.replace(R.id.album_fragment, fragment)
  transaction.commit()
}

And finally the adapter:

    class AlbumAdapter(val context: Context, private val 
    adapterCallbackAlbum: AdapterCallbackAlbum): Adapter<ViewHolder>() {
    override fun onBindViewHolder(holder: RecyclerView.ViewHolder, 
    position: Int) {
        val album = albumList[position]
        holder.itemView.setOnClickListener { 
          adapterCallbackAlbum.onClickItem(album)
       }}

But the only result I get is the second fragment put on the first one even if I call a :

transaction.remove(ListAlbumFragment.newInstance())

A friend of mine finally solved my problem (maybe it could help someone).

 override fun onClickItem(album: Album) {
    val fragment = ListTracksFragment.newInstance()
    val transaction = fragmentManager.beginTransaction()
    transaction.replace(R.id.content, fragment)
    transaction.addToBackStack(null)
    transaction.commit()
}

The trouble was we start from MainActivity, which load a fragment, inside this fragment, we have to load another one on a click event. So the fragment to replace is not the current fragment, but the content of main_activity.xml.

Thank's to all for your quick answers

Answer 1

It is simple as it is in activity just do it like this.

 override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
    super.onViewCreated(view, savedInstanceState)
    childFragmentManager.beginTransaction().replace(R.id.action_container,ChildFragment.getInstance()).commit()
}

Answer 2

Use below function inorder to add or replace any fragment

fun addFragment(
fm: FragmentManager,
fragment: Fragment,
container: Int,
replace: Boolean,
addToBackStack: Boolean,
addAnimation: Boolean
) {
val fragmentTransaction = fm.beginTransaction()
if (addAnimation)
    fragmentTransaction.setCustomAnimations(
        R.animator.slide_in_rght,
        R.animator.slide_out_left,
        R.animator.slide_in_left,
        R.animator.slide_out_rght
    )
if (replace)
    fragmentTransaction.replace(container, fragment, fragment.javaClass.name)
else
    fragmentTransaction.add(container, fragment, fragment.javaClass.name)
if (addToBackStack)
    fragmentTransaction.addToBackStack(fragment.javaClass.name)
 fragmentTransaction.commit()
}

In your fragment class where you want to open another fragment , you can call the above function :

fragmentManager?.let {
                        addFragment(
                            it, ABCFragment(), android.R.id.content, false,  true,
                            true
                        )
                    }

or

addFragment(
                        activity?.supportFragmentManager
                        , SignupFinalStepFragment.newInstance(
                            phoneNumber = phoneNumber?:"",
                            emailAddress = emailAddress ?: ""
                        ), android.R.id.content, false, addToBackStack = true,
                        addAnimation = true
                    )

Both the method calls are same , the only difference is activity?.supportFragmentManager which should be non null .

Answer 3

If you are using a Fragment, you can get the context of the activity and retrieve the fragment manager from it. So, inside your fragment class do this

FragmentManager fm = ((Activity) getContext).getSupportFragmentManager();

Not that you have your fragment manager, you only need the id of the container that you want to add/replace your other fragment and you are good to go.

fm.beginTransaction().add(R.layout.container_id, OtherFragmentObject()).commit();

Answer 4

In your CurrentFragment, override the onActivityCreated like so:

override fun onActivityCreated(savedInstanceState: Bundle?) {
    super.onActivityCreated(savedInstanceState)

    yourOwnButton.setOnClickListener{

        requireActivity().supportFragmentManager.beginTransaction()
            .replace(R.id.your_fragment_container, AnotherFragment.newInstance())
            .commit()
    }
}

and inside your AnotherFragment you should have a companion object like so:

companion object {
    fun newInstance() = StudentFragment()
}

Answer 5

   //try it 
    fun commitFragmenttoFragment(fragmentManager: FragmentManager, fragment: Fragment, tag: String) {
            val fragmentTransaction = fragmentManager.beginTransaction()
            fragmentTransaction.replace(R.`enter code here`id.fragment_main, fragment)
            fragmentTransaction.addToBackStack(null)
            fragmentTransaction.commit()
        }

    //in this fragment us activity!!.supportFragmentManager

    commitFragmenttoFragment(activity!!.supportFragmentManager,AddManageValue(), AddManageValue().TAG)

Answer 6

if anyone care, I changed second fragment to a FrameLayout after I put this code on my fragment

 childFragmentManager.beginTransaction()
            .replace(R.id.mFragment,secondFragment())
            .commit()

Answer 7

Here is how you can navigate from one fragment to another in kotlin :

<fragment
        android:id="@+id/titleFragment"
        android:name="com.dheeraj.guessbro.title.TitleFragment"
        android:label="title_fragment"
        tools:layout="@layout/title_fragment">
       <action
            android:id="@+id/action_titleFragment_to_gameFragment"
            app:destination="@id/gameFragment" />
    </fragment>

and then go to the TitleFragment.kt file and just use this code :

binding.btn_open.setOnClickListener { findNavController(this).navigate(R.id.action_titleFragment_to_gameFragment) }

If you are not using view binding then you can first define the variable using findViewById and then use the clickListener.