谷歌地图在 Android 中的 Tab Fragment 上显示为灰色

Question

I am trying to create a tab with google maps, but it's displaying grey with the google logo in the corner. I have placed the API keys in both the debug and release XML, tried to create new API keys and different solutions from other answers. But none have worked, logcat doesn't give me any errors, I suspect it has something to do with the activity code. If someone could help me I would appreciate it.

Here is my map Activity

import android.os.Bundle;

import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentTransaction;

import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import com.example.hackathon.R;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
/**
 * A simple {@link Fragment} subclass.
 */
public class MapTab extends Fragment implements OnMapReadyCallback {

    SupportMapFragment mapFragment;

    public MapTab() {
        // Required empty public constructor
    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View view = inflater.inflate(R.layout.fragment_map, container, false);
        mapFragment = (SupportMapFragment) getChildFragmentManager().findFragmentById(R.id.map);


        if(mapFragment == null){
            FragmentManager fm = getFragmentManager();
            FragmentTransaction ft = fm.beginTransaction();
            mapFragment = SupportMapFragment.newInstance();
            ft.replace(R.id.map, mapFragment).commit();
        }

        mapFragment.getMapAsync(this);
        return view;
    }

    @Override
    public void onMapReady(GoogleMap googleMap) {

    }
}

And here is my xml

<?xml version="1.0" encoding="utf-8"?>
<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=".ui.main.MapTab" >
    <fragment
        android:id="@+id/map"
        android:name="com.google.android.gms.maps.MapFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
</FrameLayout>

my manifest

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.hackathon">
    <!--
         The ACCESS_COARSE/FINE_LOCATION permissions are not required to use
         Google Maps Android API v2, but you must specify either coarse or fine
         location permissions for the 'MyLocation' functionality.
    -->
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <!--
             The API key for Google Maps-based APIs is defined as a string resource.
             (See the file "res/values/google_maps_api.xml").
             Note that the API key is linked to the encryption key used to sign the APK.
             You need a different API key for each encryption key, including the release key that is used to
             sign the APK for publishing.
             You can define the keys for the debug and release targets in src/debug/ and src/release/.
        -->
        <meta-data
            android:name="com.google.android.geo.API_KEY"
            android:value="@string/google_maps_key" />

        <activity
            android:name=".ui.main.MapsActivity"
            android:label="@string/title_activity_maps" />
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name"
            android:theme="@style/AppTheme.NoActionBar">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

Answer 1

You are not declaring map CallBack in async method.

Try this one in fragment

UPDATE

Thats my working code

public class MapFragment extends Fragment {


        public MapFragment() {
            // Required empty public constructor
        }

        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);

        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                 Bundle savedInstanceState) {
            // Inflate the layout for this fragment
            View rootView = inflater.inflate(R.layout.fragment_map, container, false);

            SupportMapFragment mapFragment = (SupportMapFragment) getChildFragmentManager().findFragmentById(R.id.frg);  //use SuppoprtMapFragment for using in fragment instead of activity  MapFragment = activity   SupportMapFragment = fragment
            mapFragment.getMapAsync(new OnMapReadyCallback() {
                @Override
                public void onMapReady(GoogleMap mMap) {
                    mMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);

                    mMap.clear(); //clear old markers

                    CameraPosition googlePlex = CameraPosition.builder()
                            .target(new LatLng(37.4219999,-122.0862462))
                            .zoom(10)
                            .bearing(0)
                            .tilt(45)
                            .build();

                    mMap.animateCamera(CameraUpdateFactory.newCameraPosition(googlePlex), 10000, null);


                    mMap.addMarker(new MarkerOptions()
                            .position(new LatLng(37.4629101,-122.2449094))
                            .title("Iron Man")
                            .snippet("His Talent : Plenty of money"));

                    mMap.addMarker(new MarkerOptions()
                            .position(new LatLng(37.3092293,-122.1136845))
                            .title("Captain America"));
                }
            });


            return rootView;
        }
       }

XML CODE

<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=".MapFragment">

    <fragment
        android:name="com.google.android.gms.maps.SupportMapFragment"
        android:id="@+id/frg"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

</FrameLayout>