构建到apk并在真实设备中安装后，Google Map不显示？

Question

我使用Google Map API构建应用程序，当我在虚拟设备上运行我的应用程序时，它正常工作，但是当我将项目构建到apk文件并将其安装在真实设备上时，它有一个问题，我的应用程序没有显示地图。 我已经在Google Developer Console中保存了调试密钥和发布密钥

我也在我的项目中输入API密钥

我启用了Google Map API

但是我的应用程序仍然无法在真实设备中运行

请帮帮我。谢谢。 这是我的代码

public class MapsActivity extends ActionBarActivity implements OnMapReadyCallback {

private GoogleMap mMap;

@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.
    SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
            .findFragmentById(R.id.map);
    mapFragment.getMapAsync(this);
}


/**
 * 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;
    // Setting a click event handler for the map
    mMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);
    mMap.setOnMapClickListener(new GoogleMap.OnMapClickListener() {

        @Override
        public void onMapClick(LatLng latLng) {

            // Creating a marker
            MarkerOptions markerOptions = new MarkerOptions();

            // Setting the position for the marker
            markerOptions.position(latLng);

            // Setting the title for the marker.
            // This will be displayed on taping the marker
            markerOptions.title(latLng.latitude + " : " + latLng.longitude);

            // Clears the previously touched position
            //mMap.clear();

            // Animating to the touched position
            mMap.animateCamera(CameraUpdateFactory.newLatLng(latLng));

            // Placing a marker on the touched position
            mMap.addMarker(markerOptions);
        }
    });


    mMap.setOnMarkerClickListener(new GoogleMap.OnMarkerClickListener() {
        @Override
        public boolean onMarkerClick(Marker marker) {
            marker.showInfoWindow();
            return true;
        }
    });
    mMap.setInfoWindowAdapter(new MyInfoWindowAdapter());
    mMap.setOnInfoWindowClickListener(new GoogleMap.OnInfoWindowClickListener() {
        @Override
        public void onInfoWindowClick(Marker marker) {
            Toast.makeText(getApplicationContext(), "Hello", Toast.LENGTH_SHORT).show();
        }
    });
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    //add(groupId, itemId, order, name)
    menu.add(1, 1, 1, "My Location");
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml
    switch (item.getItemId()) {

        case 1:
            mMap.setMyLocationEnabled(true);
            return true;

        default:
            break;

    }
    return super.onOptionsItemSelected(item);
}

class MyInfoWindowAdapter implements GoogleMap.InfoWindowAdapter {

    private final View myContentsView;

    MyInfoWindowAdapter(){
        myContentsView = getLayoutInflater().inflate(R.layout.custom_info_contents, null);
    }

    @Override
    public View getInfoContents(Marker marker) {

        TextView tvTitle = ((TextView)myContentsView.findViewById(R.id.title));
        tvTitle.setText(marker.getTitle());
        TextView tvSnippet = ((TextView)myContentsView.findViewById(R.id.snippet));
        tvSnippet.setText(marker.getSnippet());

        return myContentsView;
    }

    @Override
    public View getInfoWindow(Marker marker) {
        // TODO Auto-generated method stub
        return null;
    }

}