[GIS] How to write GML and GeoJSON features while retaining attributes in .NET

convertfields-attributesgeojsongmlnet

I am developing a .NET project [C#] that needs to export/write features as GML and GeoJSON, including, of course, the attributes; data could queried by a database or manually entered.

I checked NetTopologySuite and GeoApi, I have also tried DotSpatial and SharpMap, but none seems to be able to include attribute fields and values in the output.

Am I wrong? Is there anybody who can help me or suggest the right place to start from?

Best Answer

OGR (part of the GDAL library) ships with several language wrappers, where C# is one of them.

There is some documentation here. Here is a list of supported formats.

Also, se the API tutorial. The examples shows C++ and Python, but you should be able to get an idea how it works.

Not sure if the docs on .NET version is up to date though..

Related Solutions

[GIS] How to write GML with Geotools

I will be trying to migrate the geotools documentation to a different technology (other than wiki) so that the code examples do not go out of date.

Update this is now done (I gathered things up so all the geometry examples are together):

Here is a complete example from that page:

SimpleFeatureType TYPE = DataUtilities.createType("location", "geom:Point,name:String");

File locationFile = new File("location.xsd");
locationFile = locationFile.getCanonicalFile();
locationFile.createNewFile();

URL locationURL = locationFile.toURI().toURL();
URL baseURL = locationFile.getParentFile().toURI().toURL();

FileOutputStream xsd = new FileOutputStream(locationFile);

GML encode = new GML(Version.GML2);
encode.setBaseURL(baseURL);
encode.setNamespace("location", locationURL.toExternalForm());
encode.encode(xsd, TYPE);

xsd.close();

SimpleFeatureCollection collection = FeatureCollections.newCollection("internal");
WKTReader2 wkt = new WKTReader2();

collection.add(SimpleFeatureBuilder.build(TYPE, new Object[] { wkt.read("POINT (1 2)"),"name1" }, null));
collection.add(SimpleFeatureBuilder.build(TYPE, new Object[] { wkt.read("POINT (4 4)"),"name2" }, null));

ByteArrayOutputStream xml = new ByteArrayOutputStream();

GML encode2 = new GML(Version.GML2);
encode2.setBaseURL(baseURL);
encode2.setNamespace("location", "location.xsd");
encode2.encode(out2, collection);

xml.close();

String gml = xml.toString();

Additional examples of how to use the 4 different GML parsing technologies is the test cases included with the source code.

SAX
DOM
GTXML version 1.x (used for GML2 in WFSDataStore VERSION=1.0)
GTXML version 4.x (used for everything else now )

The two GTXML technologies are basically a combination of the best part of the SAX parser with the ability to figure out which fragment of code (called a binding) to use to parse each element as it comes in (based on looking the element up in the schema).

[GIS] GML and GeoJSON vector layer can not display in Firefox and Chrome

You could try to simplify a bit more the test, for example by removing maxResolution map option (cf. OpenLayers: Use scales instead of resolutions for more info about that configuration option).

With the debugging tools of the browser, you can also verify that wfs/json data are actually requested and received.

Best Answer

Related Solutions

[GIS] How to write GML with Geotools

[GIS] GML and GeoJSON vector layer can not display in Firefox and Chrome

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