Hot to get a Geojson string from entity?

Question

public class City
{
    public int Id { get; set; }
    public string Name { get; set; }
    public Geometry Location { get; set; }
}

My entity framework entity City type has a Geometry property. I am getting data like following:

public class CitiesController {

   public Task<IActionResult> Get(){
       var nearbyCities = context.Cities
                  .Where(c => c.Location.Distance(somePoint) < 100);

       response OK(??? geojson string ???);
   }
}

So I want how can I get Geojson string using Npgsql or Nettopologysuite?

Answer 1

You likely need to use the NetTopologySuite.IO.GeoJSON: pass the NetTopologySuite objects you get from the database to GeoJsonSerializer.

Here are some decent-looking examples.