Android Kotlin Navhost invisible problem?

Question

When I add the View Host Fragment, the design becomes invisible in the xml section, what can I do?

While navigating in Android Studio, when I add nav host fragment to the xml part, the design side becomes invisible, what can I do?

If you encounter such a problem, do not forget to give tools to the xml side in the navigation section, and do not forget to set the constrait to the nav host.

Navigation xml into

xmlns:tools="http://schemas.android.com/tools"

For example

<fragment
        android:id="@+id/firstfragment"
        android:name="com.example.countryapps.firstfragment"
        tools:layout="@layout/fragment_firstfragment"
        android:label="firstfragment" >
        <action
            android:id="@+id/action_firstfragment_to_secondfragment"
            app:destination="@id/secondfragment" />
    </fragment>