Valid WKTs for SRIDs 4326 and 3857? about projnet4geoapi HOT 6 CLOSED

You should use

// Coordinate systems
var cs4386 = ProjNet.CoordinateSystems.GeographicCoordinateSystem.WGS84;
var cs3857 = ProjNet.CoordinateSystems.ProjectedCoordinateSystem.WebMercator;

// Transformation
var ctfac = new CoordinateTransformationFactory();
var trans = ctfac.CreateFromCoordinateSystems(cs4326, cs3857);

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@Bernoulli-IT I tried to run code posted by @Rumpelstinsk and no exception is thrown

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@Bernoulli-IT tried to run code posted by @Rumpelstinsk and no exception is thrown

I think I misplaced my previous comment as I bumped into a similar issue where a conversion resulted in an incorrect y value. My bad.

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Thanks for the help. That did the trick

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Yes this helped. But why don't the WKT definitions, as mentioned by OP, lead to the correct results? That is odd and feels uncomfortable.

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Yes this helped. But why don't the WKT definitions, as mentioned by OP, lead to the correct results? That is odd and feels uncomfortable.

This is a valid question. From #37 (comment):

The issue is that the projection "Mercator_1SP" needs additional help to perform the correct conversion.
Out of the box, proj4 wouldn't compute the correct result either, that is why the Extension token is there.

Add [PARAMETER["semi_minor",6378137]] anywhere in the parameter block and you should be all set.
Or use ProjectedCoordinateSystem.WebMercator in the first place.

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