Google地图未在RecyclerView内的CardView中正确加载

Question

我是Android开发方面的新手，我在RecyclerView内部的Cardview中获得了Google地图的奇怪行为。起初，Google地图显示灰色背景，但是当我点击地图时，它会被部分加载。

有什么建议吗？提前致谢，对不起我的英语。

NotificationAdapter.java

    public class NotificationAdapter extends FirebaseRecyclerAdapter<FirebaseDBNotification, NotificationAdapter.NotificationViewHolder>  {
    private static Context context;

    public NotificationAdapter(Class<FirebaseDBNotification> modelClass, @LayoutRes int modelLayout, Class<NotificationViewHolder> viewHolderClass, Query query, Context context) {
        super(modelClass, modelLayout, viewHolderClass, query);
        this.context = context;
    }

    @Override
    protected void populateViewHolder(NotificationViewHolder viewHolder, FirebaseDBNotification model, int position) {
        viewHolder.onBindViewHolder(model,context);
    }

    public static class NotificationViewHolder extends RecyclerView.ViewHolder {
        TextView textViewLevelName,textViewLevelNumber;
        CardView cardView;
        MapView mapView;
        GoogleMap gmap;
        String position;

        public NotificationViewHolder(View itemView) {
            super(itemView);
            cardView = itemView.findViewById(R.id.card_view);
            textViewLevelName = itemView.findViewById(R.id.levelName);
            textViewLevelNumber = itemView.findViewById(R.id.levelNumber);
            mapView =  itemView.findViewById(R.id.mapLite);
        }

        public void onBindViewHolder(FirebaseDBNotification model,Context context) {
            textViewLevelName.setText("Detected " + model.getLevelName().replace('_',' ') +" air quality alert");
            textViewLevelNumber.setText("AQI level " + model.getLevelNumber());
            position = model.getPosition();
            mapView.onCreate(null);
            mapView.getMapAsync(new OnMapReadyCallback() {
                @Override
                public void onMapReady(GoogleMap googleMap) {
                    if(gmap==null) {
                        gmap = googleMap;
                        MapsInitializer.initialize(itemView.getContext());
                        String[] positionArray = position.split(",");
                        double lon = Double.parseDouble(positionArray[0]);
                        double lat = Double.parseDouble(positionArray[1]);
                        LatLng position = new LatLng(lat, lon);
                        gmap.addMarker(new MarkerOptions().position(position).title("Hello world"));
                        CameraPosition camPos = new CameraPosition.Builder()
                                .target(position)
                                .zoom(15f)
                                .build();
                        gmap.animateCamera(CameraUpdateFactory.newCameraPosition(camPos));
                    }
                }
            });
        }
    }
}

清单

<permission
        android:name="com.uca.ii.pfc.awarenessqualityair.activities.permission.MAPS_RECEIVE"
        android:protectionLevel="signature" >
    </permission>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="com.google.android.gms.permission.ACTIVITY_RECOGNITION" />
    <uses-permission android:name="com.google.android.gms.permission.ACCESS_FINE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-permission android:name="com.uca.ii.pfc.awarenessqualityair.activities.permission.MAPS_RECEIVE"/>

    <uses-feature
        android:glEsVersion="0x00020000"
        android:required="true"/>
(INSIDE <application>)
 <meta-data android:name="com.google.android.geo.API_KEY" android:value="API_KEY"/>

fragment_notification.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/notificationItemLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <android.support.v7.widget.CardView
        android:id="@+id/card_view"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:visibility="visible"
        app:cardCornerRadius="2dp"
        app:cardElevation="1dp"
        app:contentPadding="5dp">

         <LinearLayout
             android:id="@+id/layout123"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical">

             <com.google.android.gms.maps.MapView
                 android:id="@+id/mapLite"
                 android:name="com.google.android.gms.maps.MapFragment"
                 android:layout_width="match_parent"
                 android:layout_height="180dp" />

            <TextView
                android:id="@+id/levelName"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" />

            <TextView
                android:id="@+id/levelNumber"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" />

        </LinearLayout>

    </android.support.v7.widget.CardView>
</RelativeLayout>

没有点击

点击一下

两次点击

我遗失了一些东西，但我不知道是什么。