如何在片段中使用谷歌地图android SDK？

Question

I am using android maps sdk and trying to plot a point on it. I followed the steps as given here I get an NPE saying that my Support Map Fragment is null. I am guessing this happens due to the fact that I am using view binding and setting the view as binding.getroot() in my main fragment.

The code where I declared this.

  SupportMapFragment supportMapFragment = (SupportMapFragment) getActivity().getSupportFragmentManager().findFragmentById(R.id.map_view);
  supportMapFragment.getMapAsync(this::onMapReady);

The XML where I have declared this.

<androidx.fragment.app.FragmentContainerView
    android:id="@+id/map_view"
    android:name="com.google.android.gms.maps.SupportMapFragment"
    android:layout_width="match_parent"
    android:layout_gravity="center"
    android:layout_height="match_parent"/>

EDIT: Had nothing to do with View binding.

Answer 1

You should be using <fragment> tag not androidx.fragment.app.FragmentContainerView . FragmentContainerView is just a Container for fragments on which we can add fragments at runtime . on other hand <fragment> is itself a fragment this why the android:name attribute is there.

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

If you using using it a fragment you should be using getChildFragmentManager()

  SupportMapFragment supportMapFragment = (SupportMapFragment) getChildFragmentManager().findFragmentById(R.id.map_view);

Update -> Yeah sorry i was wrong earlier . turns out FragmentContainerView does support adding fragment in xml. Try the below code.

<androidx.fragment.app.FragmentContainerView
xmlns:android="http://schemas.android.com/apk/res/android"
class="com.google.android.gms.maps.SupportMapFragment"
android:id="@+id/fragmentContainerView"
android:layout_width="match_parent"
android:tag="mapFragment"
android:layout_height="match_parent" />

Then you can get the map fragment by using #findFragmentByTag .

SupportMapFragment supportMapFragment = (SupportMapFragment) getChildFragmentManager().findFragmentByTag("mapFragment");