MapFragment 不显示地图

MapFragment does not show map

我查看了文档,但找不到 MapFragment 只显示灰色屏幕且左下角带有 Google 徽标的任何原因。在我的清单中,我有应用程序级别的适当元数据(GMS 版本号和 api 键)。模块 gradle 文件具有所有需要的依赖项。错误可能在java代码中,如下:

import android.content.pm.PackageManager;
import android.location.Location;
import android.location.LocationListener;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v4.app.ActivityCompat;
import android.support.v4.app.FragmentActivity;
import android.support.v4.content.ContextCompat;

import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.location.LocationServices;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;
import com.google.android.gms.maps.model.Polyline;
import com.google.android.gms.maps.model.PolylineOptions;

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback, GoogleApiClient.ConnectionCallbacks,
        GoogleApiClient.OnConnectionFailedListener, LocationListener {

    private GoogleMap mMap;
    private Polyline polyline;
    private PolylineOptions mPLO;
    private GoogleApiClient mGoogleApiClient;
    private boolean mLocationPermissionGranted;
    private static final int PERMISSIONS_REQUEST_ACCESS_FINE_LOCATION = 1;
    private Location mLastKnownLocation;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_maps);
        // Obtain the SupportMapFragment and get notified when the map is ready to be used.
        mGoogleApiClient = new GoogleApiClient.Builder(this)
                .enableAutoManage(this /* FragmentActivity */,
                        this /* OnConnectionFailedListener */)
                .addConnectionCallbacks(this)
                .addApi(LocationServices.API)
                .build();
        mGoogleApiClient.connect();
    }


    /**
     * Manipulates the map once available.
     * This callback is triggered when the map is ready to be used.
     * This is where we can add markers or lines, add listeners or move the camera. In this case,
     * we just add a marker near Sydney, Australia.
     * If Google Play services is not installed on the device, the user will be prompted to install
     * it inside the SupportMapFragment. This method will only be triggered once the user has
     * installed Google Play services and returned to the app.
     */
    @Override
    public void onMapReady(GoogleMap googleMap) {
        mMap = googleMap;
        LatLng sydney = new LatLng(-33.852, 151.211);
        mMap.addMarker(new MarkerOptions().position(sydney)
                .title("Marker in Sydney"));
        mMap.moveCamera(CameraUpdateFactory.newLatLng(sydney));
        //mPLO = new PolylineOptions().geodesic(true);;
        //polyline = mMap.addPolyline(mPLO);

        // Turn on the My Location layer and the related control on the map.
       // updateLocationUI();

        // Get the current location of the device and set the position of the map.
        //getDeviceLocation();
    }

    @Override
    public void onConnected(@Nullable Bundle bundle) {
        SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
                .findFragmentById(R.id.map);
        mapFragment.getMapAsync(this);
    }

    @Override
    public void onConnectionSuspended(int i) {

    }

    @Override
    public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {

    }

    @Override
    public void onLocationChanged(Location location) {
       // mPLO.add(new LatLng(location.getLatitude(), location.getLongitude()));
    }

    @Override
    public void onProviderDisabled(String s) {

    }

    @Override
    public void onProviderEnabled(String s) {

    }

    @Override
    public void onStatusChanged(String s, int i, Bundle bundle) {

    }

    private void getDeviceLocation() {
        if (ContextCompat.checkSelfPermission(this.getApplicationContext(),
                android.Manifest.permission.ACCESS_FINE_LOCATION)
                == PackageManager.PERMISSION_GRANTED) {
            mLocationPermissionGranted = true;
        } else {
            ActivityCompat.requestPermissions(this,
                    new String[]{android.Manifest.permission.ACCESS_FINE_LOCATION},
                    PERMISSIONS_REQUEST_ACCESS_FINE_LOCATION);
        }
        // A step later in the tutorial adds the code to get the device location.
    }

    /**
     * Handles the result of the request for location permissions.
     */
    @Override
    public void onRequestPermissionsResult(int requestCode,
                                           @NonNull String permissions[],
                                           @NonNull int[] grantResults) {
        mLocationPermissionGranted = false;
        switch (requestCode) {
            case PERMISSIONS_REQUEST_ACCESS_FINE_LOCATION: {
                // If request is cancelled, the result arrays are empty.
                if (grantResults.length > 0
                        && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    mLocationPermissionGranted = true;
                }
            }
        }
        updateLocationUI();
    }

    /**
     * Updates the map's UI settings based on whether the user has granted location permission.
     */
    private void updateLocationUI() {
        if (mMap == null) {
            return;
        }

        /*
         * Request location permission, so that we can get the location of the
         * device. The result of the permission request is handled by a callback,
         * onRequestPermissionsResult.
         */
        if (ContextCompat.checkSelfPermission(this.getApplicationContext(),
                android.Manifest.permission.ACCESS_FINE_LOCATION)
                == PackageManager.PERMISSION_GRANTED) {
            mLocationPermissionGranted = true;
        } else {
            ActivityCompat.requestPermissions(this,
                    new String[]{android.Manifest.permission.ACCESS_FINE_LOCATION},
                    PERMISSIONS_REQUEST_ACCESS_FINE_LOCATION);
        }

        if (mLocationPermissionGranted) {
            mMap.setMyLocationEnabled(true);
            mMap.getUiSettings().setMyLocationButtonEnabled(true);
        } else {
            mMap.setMyLocationEnabled(false);
            mMap.getUiSettings().setMyLocationButtonEnabled(false);
            mLastKnownLocation = null;
        }
    }

}

logcat显示如下错误

234-31464/com.gjd.capstone E/Google Maps Android API: Authorization failure.  Please see https://developers.google.com/maps/documentation/android-api/start for how to correctly set up the map.
03-12 15:30:12.967 30234-31464/com.gjd.capstone E/Google Maps Android API: In the Google Developer Console (https://console.developers.google.com)
                                                                           Ensure that the "Google Maps Android API v2" is enabled.
                                                                           Ensure that the following Android Key exists:
                                                                            API Key: <Redacted>
                                                                            Android Application (<cert_fingerprint>;<package_name>): 47:B9:AC:D7:30:4D:AB:2D:6E:29:06:99:24:B1:7C:07:95:0A:8B:96;com.gjd.capstone

我什至查看了开发人员控制台,看看 api 是否被禁用,但事实并非如此。我仍然不确定该怎么做。我不确定 "Google Maps Android API v2" 是否启用,我找不到它的选项。

我找到了解决问题的方法。创建 MapsActivity 后,我更改了 java 文件的包,但我没有更改开发控制台中的包名称。

在另一台PC上打开项目,MapFragmant不再显示。为了解决这个问题,我在我的电脑上用密钥库签署了我的应用程序。

在 xamarin 下 1. 创建我的应用程序的存档(一个 apk) 2. 创建一个密钥库(如果尚未完成) 3.点击分发 4.选择临时 5.选择密钥库 6.点击另存为并保存到应用程序 7.重建项目