Question

我已在Android应用中实施了Google Maps API v2。当我打开包含地图片段的活动时，我添加一个标记并缩放到第14级。

以下是我添加/更新标记的方法：

private void updateMarker() {
    if(marker != null){
        marker.remove();
    }
    LatLng latlng = new LatLng(Double.parseDouble(latitude), Double.parseDouble(longitude));
    marker = mMap.addMarker(new MarkerOptions().position(latlng).title(username));
    marker.setIcon((BitmapDescriptorFactory.fromResource(R.drawable.marker)));
    mMap.moveCamera(CameraUpdateFactory.newLatLng(latlng));
    mMap.animateCamera(CameraUpdateFactory.zoomTo(zoom), 2000, null);
}

使用安装了最新Android的Nexus 5，通过Android Studio进行调试时，它可以正常工作。问题是当我运行发布版本时。标记添加到正确的位置，缩放动画正常工作，缩放到正确的级别。但它没有移动到我添加的标记。

Answer 1

您应该将CameraUpdateFactory.newLatLngZoom(latlng, zoom)的结果值传递给animateCamera，后者会返回CameraUpdate，将屏幕中心移动到由LatLng对象指定的纬度和经度，并移动到给定的缩放级别。您可以阅读更多相关信息here

Answer 2

使用此

mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(latlng, zoom));

或者

 mMap.animateCamera(CameraUpdateFactory.newLatLngZoom(latlng, zoom), 2000, null);

不要在彼此之后立即调用这两种方法。

Answer 3

实施GoogleApiClient.ConnectionCallbacks并覆盖onConnected方法，如下所示：

@Override
public void onConnected(Bundle bundle) {
    Toast.makeText(this, "onConnected", Toast.LENGTH_SHORT).show();
    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
        // TODO: Consider calling
        //    ActivityCompat#requestPermissions
        // here to request the missing permissions, and then overriding
        //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
        //                                          int[] grantResults)
        // to handle the case where the user grants the permission. See the documentation
        // for ActivityCompat#requestPermissions for more details.
        return;
    }
    mGMLastKnownLocation = LocationServices.FusedLocationApi.getLastLocation(mGMGoogleApiClient);

    try {
        // Get LocationManager object from System Service LOCATION_SERVICE
        locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

        // getting GPS status
        isGPSEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);

        // getting network status
        isNetworkEnabled = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);

        if (isGPSEnabled)  
        {
            Criteria criteria = new Criteria();
            String provider = locationManager.getBestProvider(criteria, true);
            //You can still do this if you like, you might get lucky
            mGMLastKnownLocation = locationManager.getLastKnownLocation(provider);

            if (mGMLastKnownLocation != null) {
                //place marker at current position
                mMap.clear();

                // Get latitude of the current location
                double latitude = mGMLastKnownLocation.getLatitude();

                // Get longitude of the current location
                double longitude = mGMLastKnownLocation.getLongitude();

                // Create a LatLng object for the current location
                latLng = new LatLng(latitude, longitude);

                // Show the current location in Google Map
                mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));

                // Zoom in the Google Map
                mMap.animateCamera(CameraUpdateFactory.zoomTo(7));

                MarkerOptions markerOptions = new MarkerOptions();
                markerOptions.position(new LatLng(latitude, longitude)).title("You are here!").snippet("Consider yourself located").icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_ORANGE));
                mCurrLocation = mMap.addMarker(markerOptions);

            } else {
                mGMLocationRequest = new LocationRequest();
                mGMLocationRequest.setInterval(5000); //5 seconds
                mGMLocationRequest.setFastestInterval(3000); //3 seconds
                mGMLocationRequest.setPriority(LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY);
                LocationServices.FusedLocationApi.requestLocationUpdates(mGMGoogleApiClient, mGMLocationRequest, this);
            }

        } else {
            //prompt user to enable location

            if (!locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)) {
                Intent i = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                startActivity(i);
            }
        }
    } catch (Exception e) {
        Log.e("Error : Location", "Impossible to connect to LocationManager", e);
    }

}

此外，实施LocationListener并覆盖onLocationChanged方法，如下所示：

    @Override
    public void onLocationChanged(Location location) {

    //remove previous current location marker and add new one at current position
    if (mCurrLocation != null) {
        mCurrLocation.remove();
    }

    double latitude = location.getLatitude();
    double longitude = location.getLongitude();
    latLng = new LatLng(latitude, longitude);
    mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
    mMap.animateCamera(CameraUpdateFactory.zoomTo(14));
    MarkerOptions markerOptions = new MarkerOptions();
    markerOptions.position(new LatLng(latitude, longitude)).title("Position").snippet("I am here").icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_ORANGE));
    mCurrLocation = mMap.addMarker(markerOptions);
    Toast.makeText(this, "Location Changed", Toast.LENGTH_SHORT).show();

    //If you only need one location, unregister the listener
    LocationServices.FusedLocationApi.removeLocationUpdates(mGMGoogleApiClient, this);


}

我希望它有所帮助!!

为什么谷歌地图不会缩放我提供的Lat / Long？

3 个答案: