PostGIS - Trabalhe com Camadas GIS em Bancos de Dados PostgreSQL usando C#

PostgreSQL (extensão PostGIS) são um dos bancos de dados mais amplamente utilizados entre Softwares GIS. Aspose.GIS permite que você trabalhe com os bancos de dados PostgreSQL.

Itere sobre Camadas no banco de dados PostGis

// For complete examples and data files, please go to https://github.com/aspose-gis/Aspose.GIS-for-.NET
// First, we create the connection to the PostgreSQL with Npgsql library (https://www.nuget.org/packages/Npgsql/)
// Then, we pass this connection to Dataset.Open method in order to access tables in the PostgreSQL.
using (var connection = new NpgsqlConnection(postgreSqlConnectionString))
{
    connection.Open();
    using (var ds = Dataset.Open(connection, Drivers.PostGis))
    {
        // Only spatial tables are exported as layers, so the following code will list all tables
        // that have geometry column.
        for (int i = 0; i < ds.LayersCount; ++i)
        {
            Console.WriteLine(ds.GetLayerName(i));
        }
    }
}

Adicione uma nova camada no banco de dados PostGis

// For complete examples and data files, please go to https://github.com/aspose-gis/Aspose.GIS-for-.NET
// First, we create the connection to the PostgreSQL with Npgsql library (https://www.nuget.org/packages/Npgsql/)
using (var connection = new NpgsqlConnection(postgreSqlConnectionString))
{
    connection.Open();
    // Then, we pass this connection to Dataset.Open method in order to access tables in the PostgreSQL.
    using (var ds = Dataset.Open(connection, Drivers.PostGis))
    {
        // create table with the name "features_table" and fill it with data.
        using (var layer = ds.CreateLayer("features_table"))
        {
            layer.Attributes.Add(new FeatureAttribute("name", AttributeDataType.String) { Width = 50 });

            var feature = layer.ConstructFeature();
            feature.SetValue("name", "Name1");
            feature.Geometry = Geometry.FromText("POINT (10 20 30)");
            layer.Add(feature);

            feature = layer.ConstructFeature();
            feature.SetValue("name", "Name2");
            feature.Geometry = Geometry.FromText("POINT (-10 -20 -30)");
            layer.Add(feature);
        }
    }
}

Exporte uma camada do banco de dados PostGis para um formato de arquivo

// For complete examples and data files, please go to https://github.com/aspose-gis/Aspose.GIS-for-.NET
var outputPath = Path.Combine(RunExamples.GetDataDir(), "postgres_out.shp");

// First, we create the connection to the PostgreSQL with Npgsql library (https://www.nuget.org/packages/Npgsql/)
// Then, we pass this connection to Dataset.Open method in order to access tables in the PostgreSQL.
using (var connection = new NpgsqlConnection(postgreSqlConnectionString))
{
    connection.Open();
    using (var ds = Dataset.Open(connection, Drivers.PostGis))
    {
        // open table with the name "features_table" in Postgres database and save it to the shapefile.
        using (var table = ds.OpenLayer("features_table"))
        {
            table.SaveTo(outputPath, Drivers.Shapefile);
        }
    }
}