Convert GeoJson to TopoJson or TopoJSON to GeoJSON programmatically using C#

readme.md

You can read all the details at: Convert GeoJson to TopoJson and vice versa using C#

Convert-GeoJSON-to-TopoJSON-quantization.cs

// convert GeoJSON to TopoJSON with quantization - transforming doubles to integers to reduce file size.

string SampleGeoJsonPath = dataDir + "sample.geojson";
var outputFilePath = dataDir + "convertedSampleWithQuantization_out.topojson";

// Initialize ConversionOptions class object
var options = new ConversionOptions
{
    DestinationDriverOptions = new TopoJsonOptions
    {
        // There are two ways to set quantization parameters - with Transform property or
        // with quantization number. Here we specify quantization number.
        // Quantization number specifies number of expressible values per dimension in a result
        // coordinates.
        QuantizationNumber = 100_000,

        // Alternatively, 'Transform' property can be set (but not simultaneously with quantization number).
        // Refer to TopoJSON specification for more details on transform object and quantization.
        //
        // Transform = new TopoJsonTransform(
        //     xTranslate: 0,
        //     yTranslate: 0,
        //     xScale: 0.0001000010000100001,
        //     yScale: 0.0001000010000100001),
    }
};

VectorLayer.Convert(SampleGeoJsonPath, Drivers.GeoJson, outputFilePath, Drivers.TopoJson, options);

Convert-GeoJSON-to-TopoJSON.cs

// Load input GeoJSON file
string sampleGeoJsonPath = dataDir + "sample.geojson";
var outputFilePath = dataDir + "convertedSample_out.topojson";

// convert GeoJSON to TopoJSON
VectorLayer.Convert(sampleGeoJsonPath, Drivers.GeoJson, outputFilePath, Drivers.TopoJson);

Convert-TopoJSON-to-GeoJSON.cs

// Load input TopoJSON file
var sampleTopoJsonPath = dataDir + "sample.topojson";
var outputFilePath = dataDir + "convertedSample_out.geojson";

// Convert TopoJSON to GeoJSON file
VectorLayer.Convert(sampleTopoJsonPath, Drivers.TopoJson, outputFilePath, Drivers.GeoJson);