Complete Guide to NX Open Programming with C# - Getting Started

NX Open Programming: From Beginner to Advanced with C#

Meta Description: Learn NX Open programming with C# through comprehensive tutorials, code examples, and best practices. Complete guide covering geometry creation, user interaction, and automation.

Introduction to NX Open Programming with C#

NX Open is a powerful API that allows engineers to automate common tasks, create custom applications, and extend the functionality of Siemens NX. While many existing resources focus on Visual Basic, this comprehensive guide will teach you everything using C# programming language.

What You'll Learn:

• Core NX Open concepts and architecture

• C# syntax for NX automation

• Geometry creation and manipulation

• User interface development

• File processing and data management

• Advanced programming techniques

• Setting Up Your Development Environment

Before diving into code, ensure you have:

• Visual Studio (Community Edition is free)

• Siemens NX with appropriate licenses

• .NET Framework 4.0 or higher

• NX Open .NET

// Essential using statements for NX Open C#

using System;

using NXOpen;

using NXOpen.UF;

using NXOpen.UI;

using NXOpen.Utilities;

Your First NX Open C# Program:

Let's start with a simple "Hello World" example that demonstrates the basic structure:

using System;

using NXOpen;

public class NXJournal

{

    public static void Main(string[] args)

    {

        // Get the current NX session

        Session theSession = Session.GetSession();

        // Check if we have an active part

        if (theSession.Parts.Work == null)

        {

            UI.GetUI().NXMessageBox.Show("NX Open C#", 

                NXMessageBox.DialogType.Information, 

                "No active part found. Please open a part file.");

            return;

        }

                Part workPart = theSession.Parts.Work;

        ListingWindow lw = theSession.ListingWindow;

                // Open the listing window and display information

        lw.Open();

        lw.WriteLine("Welcome to NX Open Programming with C#!");

        lw.WriteLine("Current part: {workPart.Leaf}");

        lw.WriteLine("Part units: {workPart.PartUnits}");

        lw.WriteLine("Created: {DateTime.Now}");

        lw.Close();

                // Show a message box

        UI.GetUI().NXMessageBox.Show("Success", 

            NXMessageBox.DialogType.Information, 

            "Your first NX Open C# program ran successfully!");

    }

        public static int GetUnloadOption(string dummy)

    {

        return (int)Session.LibraryUnloadOption.Immediately;

    }

}

Understanding NX Open Architecture

Session Object: The root object that provides access to all NX functionality

Session theSession = Session.GetSession();

Part Objects: Represent the CAD files you're working with

Part workPart = theSession.Parts.Work;      // Currently active part

Part displayPart = theSession.Parts.Display;  // Currently displayed part

Collections: Groups of related objects (Points, Lines, Features, etc.)

PointCollection points = workPart.Points;

CurveCollection curves = workPart.Curves;

FeatureCollection features = workPart.Features;

Creating Your First Geometry - Points in C#

Here's a practical example showing how to create points programmatically:

using System;

using NXOpen;

public class CreatePointsExample

{

    public static void Main(string[] args)

    {

        Session theSession = Session.GetSession();

        Part workPart = theSession.Parts.Work;

        if (workPart == null)

        {

            UI.GetUI().NXMessageBox.Show("Error", 

                NXMessageBox.DialogType.Error, 

                "No active part found!");

            return;

        }

        // Set undo mark

        Session.UndoMarkId markId = theSession.SetUndoMark(

            Session.MarkVisibility.Visible, "Create Points");

        try

        {

            // Create points at specific coordinates

            Point3d[] coordinates = {

                new Point3d(0, 0, 0),

                new Point3d(10, 0, 0),

                new Point3d(10, 10, 0),

                new Point3d(0, 10, 0),

                new Point3d(5, 5, 5)

            };

            Point[] points = new Point[coordinates.Length];

            for (int i = 0; i < coordinates.Length; i++)

            {

                // Create the point

                points[i] = workPart.Points.CreatePoint(coordinates[i]);

                // Make it visible

                points[i].SetVisibility(SmartObject.VisibilityOption.Visible);

                // Set properties

                points[i].Color = 6; // Magenta

                points[i].Layer = 1;

                // Set a name

                points[i].SetName("Point_{i + 1}");

            }

            // Update the display

            theSession.UpdateManager.DoUpdate(markId);

            UI.GetUI().NXMessageBox.Show("Success", 

                NXMessageBox.DialogType.Information, 

                "Created " + coordinates.Length + " points successfully!");

        }

        catch (Exception ex)

        {

            theSession.UndoToMark(markId, "Create Points");

            UI.GetUI().NXMessageBox.Show("Error", 

                NXMessageBox.DialogType.Error, 

                "Error creating points: {ex.Message}");

        }

    }

    public static int GetUnloadOption(string dummy)

    {

        return (int)Session.LibraryUnloadOption.Immediately;

    }

}

Working with Selections - User Interaction

One of the most powerful features is allowing users to interact with your programs: