Getting Android Fragment no view found for ID

Question

First of, I've checked this question has been done and have tested the solutions that are explained on this site (although I may have committed errors in doing them as there are so many possible causes for the error).

I mean solutions like the ones offered here:

Android Fragment no view found for ID?

And here:

Android Fragment: No view found for id 0x7f040034

So, I'm explaining my particular case.

First of, I'm setting the layout like this in my fragment:

 public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        root = inflater.inflate(R.layout.activity_calendario_laboral, container, false);
        return root;
    }

That layout is, summarized, as it follows:

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/main_content"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:id="@+id/principal">
[...]
</LinearLayout>
</FrameLayout>

Once the view has been created I get to call this method:

final Fragment thisFragment=this;
KotlinClass.Companion.setCalendarViewdateListener(calendarView,thisFragment,R.id.principal);

In that method of KotlinClass I get to call this function:

setFragment(FichajesFragment(), fragment,"Fichajes",id);

Being the parameter fragment the thisFragment passed to setCalendarViewdateListener function.

I've finally defined setFragment like this:

private fun setFragment(fragment: Fragment, fragment2: Fragment, tag: String, id: Int) {
                    val fragmentManager: FragmentManager = fragment2.activity!!.getSupportFragmentManager();
 val fragmentTransaction = fragmentManager.beginTransaction()
 for (activeFragment in fragmentManager.fragments) {
          fragmentTransaction.remove(activeFragment)
 }
 fragmentTransaction.add(id, fragment, tag)
 fragmentTransaction.commit()
 fragmentManager.executePendingTransactions()
 
}

It raises an exception when executing fragmentManager.executePendingTransactions() telling that no view found for id, refering to the principal id of the linearlayout.

What am I missing?

Answer 1

If I understand correctly, I think in your layout file you have to specify parameter: tools:context=".FragmentName"

Answer 2

I noticed several issues, but the main problem why your app is crashing is because of this part:

 val fragmentManager: FragmentManager = fragment2.activity!!.getSupportFragmentManager();
 val fragmentTransaction = fragmentManager.beginTransaction()
 for (activeFragment in fragmentManager.fragments) {
          fragmentTransaction.remove(activeFragment)
 }

Into fragmentManager you stored the fragmentManager that belongs to the activity that hosts the fragment2 , in your case the fragment with the layout including the Linearlayout with @+id/principal id. Then in your for loop, you remove all the fragments that are managed by that fragmentManager , which means you removed the fragment2 from it too. So when you later call:

fragmentTransaction.add(id, fragment, tag)

it can't find any view with the id @+id/principal , because the fragment containing that Linearlayout ( fragment2 ) was just removed.

So for your code to work, remove the for loop and the app should not crash anymore. But the way your code samples look, I assume you want to add FichajesFragment as part of the fragment2 , in which case you are using wrong fragmentManager ; instead of the activity one, you should use the one that belongs to fragment2 , ie:

val fragmentManager: FragmentManager = fragment2.childFragmentManager

One more note: I got confused by the R.layout.activity_calendario_laboral , but the layout is actually for the fragment, if I understood it correctly, so just so you know.