Duplicate id, tag null, with another fragment for androidx.navigation.fragment.NavHostFragment

Question

Issue I am trying to add a fragment in activity, along with Navigation. But I see the following error

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.app.myapp/com.app.myapp.HomeMainActivity}: android.view.InflateException: Binary XML file line #12: Binary XML file line #12: Error inflating class fragment
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2927)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2988)
    at android.app.ActivityThread.-wrap14(ActivityThread.java)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1631)
    at android.os.Handler.dispatchMessage(Handler.java:102)
    at android.os.Looper.loop(Looper.java:154)
    at android.app.ActivityThread.main(ActivityThread.java:6682)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1520)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1410)
 Caused by: android.view.InflateException: Binary XML file line #12: Binary XML file line #12: Error inflating class fragment
 Caused by: android.view.InflateException: Binary XML file line #12: Error inflating class fragment
 Caused by: java.lang.IllegalArgumentException: Binary XML file line #12: Duplicate id 0x7f0900ed, tag null, or parent id 0xffffffff with another fragment for androidx.navigation.fragment.NavHostFragment

Code

1. activity_home_new.xml

       <?xml version="1.0" encoding="utf-8"?>
      <layout 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">
         <androidx.constraintlayout.widget.ConstraintLayout
           android:layout_width="match_parent"
           android:layout_height="match_parent"
           android:background="@color/colorPrimaryDark"
           tools:context=".HomeMainActivity">
   
           <fragment
           android:id="@+id/my_nav_host_fragment"
           android:name="androidx.navigation.fragment.NavHostFragment"
           android:layout_width="0dp"
           android:layout_height="0dp"
           app:defaultNavHost="true"
           app:layout_constraintBottom_toBottomOf="parent"
           app:layout_constraintEnd_toEndOf="parent"
           app:layout_constraintStart_toStartOf="parent"
           app:layout_constraintTop_toTopOf="parent"
           app:navGraph="@navigation/nav_graph" />
          </androidx.constraintlayout.widget.ConstraintLayout>
   
          </layout>
   

No changes made in Fragment and Activity class.

Solution which I tried

I tried changing fragment to framelayout and FragmentContainerView in ctivity_home_new.xml The app doesn't; crash.

My opinion about the crash

The crash is something related to with "androidx.navigation.fragment.NavHostFragment". There are few questions something similar that is related to MapFragment.

Not looking for the code, I just want to know the root cause for the crash

Answer 1

It seems that NavHostFragment is just a coincidental passwalker. This problem is related to inflating XML content twice.

In my case what I was doing:

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

        binding = ActivitySigninBinding.inflate(layoutInflater)
        setContentView(R.layout.activity_signin)
}

and it was working until I split my content into more fragments. The fix was:

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

        binding = ActivitySigninBinding.inflate(layoutInflater)
        setContentView(binding.root) // Notice the binding root
}

Hope it helps, spend some time to figure it out.