[gdal-dev] Convert ESRI Shapefile to GeoJSON in memory, code in c#

[Paul Harwood]

I have a working c# GDAL app - I might be able to help.

I am not sure I understand what you are trying to do? It looks like you are
creating a GeoJSON file from a shapefile and that actually only makes any
sense if you want to save the file?

>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> * private FeatureCollection ImportShapeFile(IEnumerable<ImportFile>
> files)        {            var tempJsonFilename = $"/vsimem/temp.json";
>         GdalConfiguration.ConfigureGdal();
> GdalConfiguration.ConfigureOgr();            try            {
>   // Copy into GDAL                foreach (var file in files)
>   {                    Gdal.FileFromMemBuffer($"/vsimem/{file.Filename}",
> file.Data);                }*
>

>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> *                // Load shape                var shpDriver =
> Ogr.GetDriverByName("ESRI Shapefile");                var shpFile =
> files.First(f => f.Filename.EndsWith(".shp"));                var
> shpDatasource = Ogr.Open($"/vsimem/{shpFile.Filename}", 0);
> if (shpDatasource == null)                    return null;
> var shpLayer = shpDatasource.GetLayerByIndex(0);                // Setup
> projection transform to WGS84                var srcProjection =
> shpLayer.GetSpatialRef();                var destProjection = new
> SpatialReference("");                destProjection.ImportFromEPSG(4326);
>               var transform = new CoordinateTransformation(srcProjection,
> destProjection);                // Copy layer to geo json
> var jsonDriver = Ogr.GetDriverByName("GeoJSON");                var
> jsonDataSource = jsonDriver.CreateDataSource(tempJsonFilename, new string[]
> { });                var jsonLayer =
> jsonDataSource.CreateLayer(shpLayer.GetName(), destProjection,
> shpLayer.GetGeomType(), new string[] { });                var shpFeature =
> shpLayer.GetNextFeature();                while (shpFeature != null)
>         {                    // Transform geometry                    var
> geometry = shpFeature.GetGeometryRef();
> geometry.Transform(transform);                    // Save feature to new
> layer                    jsonLayer.CreateFeature(shpFeature);
>       shpFeature = shpLayer.GetNextFeature();                }
>   // TODO: HERE I would like to read the information from my tempJsonFile
> back into a byte array, before unlinking.                var jsonBuffer =
> new byte[0];                // Close all GDAL stuff
> jsonLayer.Dispose();                jsonDataSource.Dispose();
>   jsonDriver.Dispose();                shpLayer.Dispose();
> shpDatasource.Dispose();                shpDriver.Dispose();
> // Read json from buffer                var jsonText =
> Encoding.UTF8.GetString(jsonBuffer, 0, jsonBuffer.Length); ;
> var json = JsonConvert.DeserializeObject<FeatureCollection>(jsonText);
>           return json;            }            catch (Exception exception)
>           {                throw exception;            }
> finally            {                // Clear files from GDAL
> Gdal.Unlink(tempJsonFilename);                foreach (var file in files)
>               {
> Gdal.Unlink($"/vsimem/{file.Filename}");                }            }
>   }*
>
>
> Best Regards
> Christian
>
> --
>
> *Christian Sörensen*
> *UX Productions AB*
> www.uxproductions.se | christian at uxproductions.se | +46 (0)70 26 77 212
> P Överväg miljöpåverkan innan du skriver ut detta e-postmeddelande
> _______________________________________________
> gdal-dev mailing list
> gdal-dev at lists.osgeo.org
> https://lists.osgeo.org/mailman/listinfo/gdal-dev
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/gdal-dev/attachments/20201111/a77a0e10/attachment.html>