谷歌地图在Android的Tab Fragment上显示灰色

Question

我正在尝试使用谷歌地图创建一个标签，但它显示为灰色，角落里有谷歌标志。我已经将API密钥放在调试和发布XML中，尝试创建新的API密钥和其他答案不同的解决方案。但是没有一个工作，logcat没有给我任何错误，我怀疑它与活动代码有关。 如果有人能帮助我，我将不胜感激。

这是我的地图活动

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) {
}
}

这是我的 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>

我的清单

<?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

您不是在异步方法中声明映射回调。

在片段中尝试这个

更新

那是我的工作代码

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代码

<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>