使用NavController从一个活动导航到另一个活动

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

<navigation xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <fragment
        android:id="@+id/firstFragment"
        android:name="com.example.app.FirstFragment"
        android:label="First Fragment">
        <action
            android:id="@+id/action_firstFragment_to_secondFragment"
            app:destination="@id/secondFragment" />
    </fragment>

    <fragment
        android:id="@+id/secondFragment"
        android:name="com.example.app.SecondFragment"
        android:label="Second Fragment">
        <action
            android:id="@+id/action_secondFragment_to_thirdFragment"
            app:destination="@id/thirdFragment" />
    </fragment>

    <fragment
        android:id="@+id/thirdFragment"
        android:name="com.example.app.ThirdFragment"
        android:label="Third Fragment" />

</navigation>

NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment);
navController.navigate(R.id.action_firstFragment_to_secondFragment);