android - mapFragment.getMapAsync(this) - NullPointerException

Question

I am using com.google.android.gms:play-services-maps:7.5.0 version of Google Maps services. When trying to call the below I get java.lang.NullPointerException: Attempt to invoke virtual method 'void com.google.android.gms.maps.SupportMapFragment.getMapAsync(com.google.android.gms.maps.OnMapReadyCallback)' on a null object reference.

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    SupportMapFragment mapFragment = (SupportMapFragment) getActivity().getSupportFragmentManager()
            .findFragmentById(R.id.map);
    mapFragment.getMapAsync(this); //error

    return inflater.inflate(R.layout.fragment_example_map, container, false);
}

fragment_example_map.xml file:

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="app.ExampleMap">

    <fragment xmlns:android="http://schemas.android.com/apk/res/android"
        android:name="com.google.android.gms.maps.SupportMapFragment"
        android:id="@+id/map"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>
</FrameLayout>

question from:https://stackoverflow.com/questions/30991087/mapfragment-getmapasyncthis-nullpointerexception

Answer 1

You are attempting to find a fragment before it exists. You indicate that the layout that has the fragment is fragment_example_map.xml. However, you are trying to find the map fragment before you inflate that layout file. This will not work.

Beyond that, you appear to be trying to get at the map fragment from inside another fragment, in that fragment's onCreateView() method. I do not know why you are nesting fragments here, as it seems like it will make your code more complex and more fragile for no obvious benefit.