Please provide proper documentation

[FrankyBoy]

It is very hard to figure out how to actually use this library to load a geometry from a geopackage - which I'd assume is the whole point of it.

[FrankyBoy]

Specifically I'd like to see simple examples for reading and writing geopackages, and maybe one with dapper.

For reading that could be something like this ... (I'm not writing packages, so someone else will have to provide that one)

Reading features from geopackage:

Required Packages:

• Microsoft.Data.Sqlite
• NetTopologySuite.IO.GeoPackage

Dictionary<string, Geometry> features = [];

await using connection = new SqliteConnection("Data Source=myfile.gpkg");
await connection.OpenAsync();
await using SqliteCommand command = connection.CreateCommand();
command.CommandText = """
    SELECT geom, featurename
    FROM layer_name
    """;

var gpkgReader = new GeoPackageGeoReader();
await using SqliteDataReader dataReader = command.ExecuteReader();
while (await dataReader.ReadAsync())
{
    byte[] geometryBlob = await dataReader.GetFieldValueAsync<byte[]>(0);
    var geometry = gpkgReader.Read(geometryBlob);
    string name = dataReader.GetString(1);
    features[name] = geometry;
}

Reading features using Dapper:

Required Packages:

• Microsoft.Data.Sqlite
• NetTopologySuite.IO.GeoPackage
• Dapper

Support classes:

private class MyFeature
{
    public string FeatureName { get; set; }
    public Geometry Geom { get; set; }
}

private class GeometryTypeHandler(GeoPackageGeoReader reader) : TypeHandler<Geometry>
{
    public override Geometry Parse(object value)
    {
        return reader.Read((byte[])value);
    }

    public override void SetValue(IDbDataParameter parameter, Geometry value)
    {
        throw new NotImplementedException();
    }
}

    AddTypeHandler(new GeometryTypeHandler(new GeoPackageGeoReader(), null));

    await using SqliteConnection connection = new("Data Source=myfile.gpkg");
    await connection.OpenAsync();

    var geometries = await connection.QueryAsync<MyFeature>("""
        SELECT geom, featurename
        FROM layer_name
        """);