Create Vector Layer with SRS

Introduction

Aspose.GIS for .NET is a powerful library that enables developers to work with geographic information system (GIS) data seamlessly in .NET applications. In this tutorial, we’ll focus on creating a vector layer with a spatial reference system (SRS). By the end of this guide, you’ll be able to effortlessly integrate GIS capabilities into your .NET projects.

Prerequisites

Before we dive into the tutorial, make sure you have the following prerequisites in place:

• Basic knowledge of C# and .NET development.
• Aspose.GIS for .NET library installed. You can download it here.
• A development environment set up and ready.

Import Namespaces

Ensure you have the necessary namespaces imported at the beginning of your C# file:

using Aspose.Gis;
using Aspose.Gis.Formats.Shapefile;
using Aspose.Gis.Geometries;
using Aspose.Gis.SpatialReferencing;
using Aspose.GIS.Examples.CSharp;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

Step 1: Set Up the Projected Spatial Reference System

Let’s create a projected spatial reference system (SRS) using the World Mercator projection as an example. Follow these steps:

var parameters = new ProjectedSpatialReferenceSystemParameters
{
    Name = "WGS 84 / World Mercator",
    Base = SpatialReferenceSystem.Wgs84,
    ProjectionMethodName = "Mercator_1SP",
    LinearUnit = Unit.Meter,
    XAxis = new Axis("Easting", AxisDirection.East),
    YAxis = new Axis("Northing", AxisDirection.North),
    AxisesOrder = ProjectedAxisesOrder.XY,
};
parameters.AddProjectionParameter("central_meridian", 0);
parameters.AddProjectionParameter("scale_factor", 1);
parameters.AddProjectionParameter("false_easting", 0);
parameters.AddProjectionParameter("false_northing", 0);
var projectedSrs = SpatialReferenceSystem.CreateProjected(parameters, Identifier.Epsg(3395));

Step 2: Create a Vector Layer and Add Features

Now, let’s create a shapefile and add features with the specified SRS:

using (var layer = Drivers.Shapefile.CreateLayer(dataDir + "filepath_out.shp", new ShapefileOptions(), projectedSrs))
{
    var feature = layer.ConstructFeature();
    feature.Geometry = new Point(1, 2);
    layer.Add(feature);
    feature = layer.ConstructFeature();
    feature.Geometry = new Point(1, 2) { SpatialReferenceSystem = SpatialReferenceSystem.Nad83 };
    try
    {
        layer.Add(feature); // This will throw an exception as the geometry has a different SRS
    }
    catch (GisException e)
    {
        Console.WriteLine(e.Message);
    }
}

Step 3: Verify Spatial Reference System

Finally, let’s open the layer and verify its spatial reference system:

using (var layer = Drivers.Shapefile.OpenLayer(dataDir + "filepath_out.shp"))
{
    var srsName = layer.SpatialReferenceSystem.Name; // "WGS 84 / World Mercator"
    layer.SpatialReferenceSystem.IsEquivalent(projectedSrs); // Should return true
}

By following these steps, you’ve successfully created a vector layer with a specified spatial reference system using Aspose.GIS for .NET.

Conclusion

Integrating GIS functionality into your .NET applications has never been easier, thanks to Aspose.GIS. With the ability to effortlessly create vector layers and manage spatial reference systems, you can enhance your projects with powerful geospatial capabilities.

FAQs

Is Aspose.GIS compatible with all GIS file formats?

Aspose.GIS supports various GIS formats, including Shapefile, GeoJSON, KML, and more. Check the documentation for the complete list.

Can I use Aspose.GIS in a web application?

Absolutely! Aspose.GIS for .NET is versatile and can be used in web applications, desktop applications, and even mobile apps.

Where can I get support for Aspose.GIS?

You can find a helpful community at the Aspose.GIS forum for any queries or issues you may encounter.

Is there a free trial available?

Yes, you can explore the features of Aspose.GIS by obtaining a free trial here.

How can I purchase a license for Aspose.GIS?

To purchase a license, visit the purchase page.