Navigation error - This navigation graph is not referenced to any layout files?

Issue

I am trying to apply navigation feature to my project.

And I have this error:

This navigation graph is not referenced to any layout files(expected to find it in at least one layout file with a NavHostFragment with app:navGraph="@navigation/@navigation" attribute

<?xml version="1.0" encoding="utf-8"?>
<navigation 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"
    android:id="@+id/navigation"
    android:label="fragment_init"
    app:startDestination="@id/initFragment"
    >

    <fragment
        android:id="@+id/initFragment"
        android:label="fragment_init"
        tools:layout="@layout/fragment_init">
        <action
            android:id="@+id/action_initFragment_to_authenticationFragment5"
            app:destination="@id/authenticationFragment"
            />
        <action
            android:id="@+id/action_initFragment_to_settingFragment3"
            app:destination="@id/settingFragment" />
    </fragment>
    <fragment
        android:id="@+id/authenticationFragment"
        android:name="com.example.AuthenticationFragment"
        android:label="fragment_authentication"
        tools:layout="@layout/fragment_authentication" />
    <fragment
        android:id="@+id/settingFragment"
        android:name="com.example.view.main.fragment.SettingFragment"
        android:label="SettingFragment"
        tools:layout="@layout/fragment_setting" />
</navigation>

I added that attribute here and there (navigation and fragments ). And also, the layout files in layout folder which are used in navigation.xml. But didn't work.

This is activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#000"
    android:tint="#555"
    tools:context=come.example.view.main.MainActivity">

    <ImageView
        android:id="@+id/iv_flame"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_centerInParent="true" />

    <fragment
        android:id="@+id/nav_host_fragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:navGraph="@navigation/navigation"/>
</RelativeLayout>

Solution

You haven't set up for your <fragment> correctly - every <fragment> needs an android:name pointing to the Fragment class it is loading. In the case of Navigation, it must reference the androidx.navigation.fragment.NavHostFragment as per the Getting Start documentation:

<fragment
    android:id="@+id/nav_host_fragment"
    android:name="androidx.navigation.fragment.NavHostFragment"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:defaultNavHost="true"
    app:navGraph="@navigation/navigation"/>

Once you actually tie your navigation graph to a NavHostFragment, the error will go away.

Answered By - ianhanniballake