Google地图未在Android片段中完全加载（部分加载问题）

Question

我正在开发一个Android应用程序，需要将Google地图加载到片段中。 地图仅部分加载。地图的一半仍然是灰色的，不会加载。 请提供您的建议。我不确定这个问题。

以下是项目文件：

MapFragment.java：

public class MapFragment extends Fragment {


    MapView mMapView;
    GoogleMap googleMap;
    Context context;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {


        // inflat and return the layout
        View v = inflater.inflate(R.layout.fragment_map, container, false);
        mMapView = (MapView) v.findViewById(R.id.mapView);
        mMapView.onCreate(savedInstanceState);

        mMapView.onResume();// needed to get the map to display immediately



        try {
            MapsInitializer.initialize(getActivity().getApplicationContext());
        } catch (Exception e) {
            e.printStackTrace();
        }


        context = getContext();

        DatabaseHelper databaseHelper = new DatabaseHelper(context, null, null, 0);
        ArrayList<PropertyDetails> arrayList = databaseHelper.readData();
        Log.d("PAVAN", "Details "+arrayList.get(0).getCity());
        Log.d("PAVAN", "Details "+arrayList.get(0).getLatitude());

        googleMap = mMapView.getMap();


        for(int i = 0 ; i < arrayList.size() ; i++) {

            // latitude and longitude
            String PropertyType = arrayList.get(i).PropertyType;
            String Address = arrayList.get(i).Address;
            String City = arrayList.get(i).City;
            Double LoanAmount = arrayList.get(i).LoanAmount;
            Double APR = arrayList.get(i).APR;
            Double MonthlyPayment = arrayList.get(i).MonthlyPayment;
            Double Latitude = arrayList.get(i).getLatitude();
            Double Longitude = arrayList.get(i).getLongitude();


            // create marker
            MarkerOptions marker = new MarkerOptions().position(
                    new LatLng(Latitude, Longitude)).title(PropertyType + "<br/>" + Address + "<br/>" +
                    City + '\n' + LoanAmount + '\n' + APR + "<br/>" + MonthlyPayment).snippet("" + APR).snippet("" + MonthlyPayment);

            // Changing marker icon
            marker.icon(BitmapDescriptorFactory
                    .defaultMarker(BitmapDescriptorFactory.HUE_ROSE));

            // adding marker
            googleMap.addMarker(marker);
            CameraPosition cameraPosition = new CameraPosition.Builder()
                    .target(new LatLng(17.385044, 78.486671)).zoom(12).build();
            //  googleMap.setInfoWindowAdapter(CustomWindowAdapter);
            googleMap.animateCamera(CameraUpdateFactory
                    .newCameraPosition(cameraPosition));

        }

        // Perform any camera updates here
        return v;

    }

    @Override
    public void onResume() {
        super.onResume();
        mMapView.onResume();
    }

    @Override
    public void onPause() {
        super.onPause();
        mMapView.onPause();
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        mMapView.onDestroy();
    }

    @Override
    public void onLowMemory() {
        super.onLowMemory();
        mMapView.onLowMemory();
    }


}

fragment_map.xml

<RelativeLayout 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"
android:paddingTop="8dp"
tools:context="com.example.pavanshah.mortgagecalculator.MainActivity$PlaceholderFragment">

<com.google.android.gms.maps.MapView
    android:id="@+id/mapView"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

</RelativeLayout>

清单文件：

<?xml version="1.0" encoding="utf-8"?>

<uses-feature
    android:glEsVersion="0x00020000"
    android:required="true" />

<uses-permission android:name="android.permission.INTERNET"></uses-permission>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"></uses-permission>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"></uses-permission>

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">

    <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>

    <meta-data android:name="com.google.android.gms.version"
        android:value="@integer/google_play_services_version">
    </meta-data>


    <meta-data android:name="com.google.android.geo.API_KEY"
        android:value="My_Key">
    </meta-data>

</application>

截图：