GstarCAD 2026 .NET Programming Guide

Contents

• #Table of Conents
• #1. Introduction
• #2. Programming Environment
• #3. Install GstarCAD SDK
• #4. Visual Studio 2022 C# .NET Programming Sample
  • #4.1.2. Input Project Save Path and Project Name
  • #4.1.3. Finish Creating New Project
  • #4.2. Set Reference Library
    • #4.2.1. Add Reference
    • #4.2.2. Choose and Add Reference File
  • #4.3. Add Code
  • #4.4. Compile Program
  • #4.5. Run Program
• #5. Visual Studio 2022 VB .NET Programming Sample
  • #5.1.2. Input Project Save Path and Project Name
  • #5.1.3. Finish Creating New Project
  • #5.2. Set the Reference
    • #5.2.1. Add Reference
    • #5.2.2. Choose and Add Reference File
  • #5.3. Add code
  • #5.4. Compile Program
  • #5.5. Run Program
• #6. C# .NET and VB .NET Namespace Modification
• #7. Copyright

Table of Conents

1. Introduction

GstarCAD .NET API provides a series of Managed Wrapper Class, Object-oriented development environment and API on the basic of .NET. Developers can use the languages which support .NET language, such as VB .NET, C# to develop application on GstarCAD.

2. Programming Environment

• Microsoft® Visual Studio 2022 (version 17.8.0)

• Windows SDK 10.0 (latest installed version)

• CPU:

Basic: 1.6 GHz CPU

Recommended: 3.0 GHz CPU and above

• RAM:

Basic: 2 GB

Recommended: 8 GB and above

• Operation System (OS)

Windows 11

Windows 10 (version 1507 and above):

Home, Professional, Education and Enterprise (not support LTSC and Windows 10 S)

Windows 8.1 (with 2919355 update):

Core, Professional and Enterprise

Windows 7 SP1 (with the latest update):

Home, Professional, Enterprise and Ultimate

• Monitor Resolution:

1028x800 and above true color display, including 4K (3840x2160) display

• GstarCAD SDK 2026

• GstarCAD 2026

• Microsoft .NET 8.0

3. Install GstarCAD SDK

Download GstarCAD SDK (' GRXSDK.ZIP ' file) from GstarCAD website:

https://www.gstarcad.net/download/

Unzip GRXSDK.ZIP file to the local disk (e.g. 'C:\grxsdk' ) and there will be 5 directories generated (in 'C:\grxsdk' ) which are: arx , inc , inc-x64 , lib-x64 and utils .

arx contains the header files, library files and sample programs used for porting ARX programs to GRX programs. It contains the following directories:

• inc: Header files used for porting from ARX to GRX

• inc-x64 : Files used by COM and .NET (for 64-bit)

• lib-x64 : GRX libraries (for 64-bit)

• Samples : Sample projects, including Dotnet, fact_dg, HelloADS, HelloA and SimplePalette.

• Dotnet : .NET programming samples

• 1. Addline : .NET programming sample of adding solid lines
• 2. Hello : .NET programming sample of outputting prompt information
• 3. Vbhello : Sample of .NET programming with VB .NET

• fact_dg : Sample of LISP function definition

• HelloADS : Sample of ADS programming

• HelloARX : Sample of GRX programming

• SimplePalette : Programming sample of how to create a set Palette windows

• Utils: Directory contains sub-directories of GRX extended applications, including APIs for extended function development,

e.g. BREP for boundary representation.

Inc: Header files used for programming the GRX

inc-x64 : Files used by COM and .NET (for 64-bit) lib-x64 : GRX libraries (for 64-bit)

Utils : Directory contains subdirectories of GRX extended applications, including APIs for extended function development, e.g. BREP for boundary representation.

4. Visual Studio 2022 C# .NET Programming Sample

The following is an example of how to create a project called ' AddLine ', assuming that the GstarCAD SDK is installed in the ' C:\grxsdk '.

• 4.1. Create .NET project

• 4.1.1. Runn Microsoft® Visual Studio 2022

Click File → New → Project to launch the New Project dialog window. Select C# from the drop down list on the right side and click Class Library from the list frame.

4.1.2. Input Project Save Path and Project Name

Input ' AddLine ' at the Project Name field in the New Project dialog box, enter ' C:\Sample\dotNet ” in the Location field, and click Next . As shown below.

4.1.3. Finish Creating New Project

Select .NET 8.0 (Long Term Support) in the drop-down list and click the Create button to finish creating the new project ' AddLine '.

4.2. Set Reference Library

4.2.1. Add Reference

In Visual Studio 2022, find the ' AddLine ' project in the Solution Explorer , right-click on it and select Add → Reference .

After the Reference Manager dialog window pops out, click Browse as shown below.

4.2.2. Choose and Add Reference File

From the GstarCAD SDK installation directory, e.g. ' C:\grxsdk' , select 'GcCoreMgd.dll', 'GcDbMgd.dll' and 'GcMgd.dll' in ' \arx\inc ' and 'GrxCAD.Interop.dll '(or ' acax.tlb ') in ' \arx\inc-x64 ', and add them by clicking Add button.

when COM is used in the program).

After adding the files, right-click added ' GcCoreMgd.dll', 'GcDbMgd.dll' and 'GcMgd.dll' files and select Properties at the context menu, the Reference Properties palette pops up. Set the value of Copy Local property to False . The following screenshot shows how to change Copy Local property of ' GcCoreMgd.dll '.

• ' GcCoreMgd.dll ' includes the following namespaces:

Gssoft.Gscad.ApplicationServices Gssoft.Gscad.ApplicationServices.Core Gssoft.Gscad.EditorInput Gssoft.Gscad.GraphicsSystem Gssoft.Gscad.Internal Gssoft.Gscad.PAL.FontUtils Gssoft.Gscad.PlottingServices Gssoft.Gscad.Publishing Gssoft.Gscad.Runtime Gssoft.Gscad.Windows

 ' GcDbMgd.dll ' includes the following namespaces: Gssoft.Gscad Gssoft.Gscad.Colors Gssoft.Gscad.ComponentModel Gssoft.Gscad.DatabaseServices Gssoft.Gscad.DatabaseServices.Filters Gssoft.Gscad.DatabaseServices.Internal Gssoft.Gscad.Geometry Gssoft.Gscad.GraphicsInterface Gssoft.Gscad.GraphicsSystem Gssoft.Gscad.Internal Gssoft.Gscad.LayerManager Gssoft.Gscad.PAL.FontUtils Gssoft.Gscad.Runtime

 'GcMgd.dll' includes the following namespaces: Gssoft.Gscad.ApplicationServices Gssoft.Gscad.EditorInput Gssoft.Gscad.Internal Gssoft.Gscad.Internal.Calculator Gssoft.Gscad.Internal.DatabaseServices Gssoft.Gscad.Internal.Forms Gssoft.Gscad.Internal.PreviousInput Gssoft.Gscad.Internal.PropertyInspector Gssoft.Gscad.Internal.Reactors Gssoft.Gscad.Internal.Render.RapidRT Gssoft.Gscad.Internal.Windows Gssoft.Gscad.PAL.FontUtils Gssoft.Gscad.Windows Gssoft.Gscad.Windows.Data Gssoft.Gscad.Windows.Data.Render.RapidRT Gssoft.Gscad.Windows.ToolPalette

• ' GrxCAD.Interop.dll ' shows the corresponding .NET APIs of COM.

4.3. Add Code

Add the following codes to 'Class1.cs':

using Gssoft.Gscad.ApplicationServices;
using Gssoft.Gscad.DatabaseServices;
using Gssoft.Gscad.Geometry;
using Gssoft.Gscad.Runtime;

namespace AddLine
{
    public class Class1
    {
        [CommandMethod("addline")]
        static public void DoIt()
        {
            Point3d st = new Point3d(100.0, 100.0, 0.0);
            Point3d ed = new Point3d(200.0, 200.0, 0.0);
            Line lin = new Line(st, ed);
            Database db = HostApplicationServices.WorkingDatabase;
            Transaction trans = db.TransactionManager.StartTransaction();
            try
            {
                BlockTable bt = (BlockTable)trans.GetObject(db.BlockTableId,
OpenMode.ForRead);
                BlockTableRecord btr =
(BlockTableRecord)trans.GetObject(bt[BlockTableRecord.ModelSpace], OpenMode.ForWrite);
                btr.AppendEntity(lin);
                trans.AddNewlyCreatedDBObject(lin, true);
                trans.Commit();
            }
            catch (System.Exception ex)
            {

Application.DocumentManager.MdiActiveDocument.Editor.WriteMessage(ex.ToString());
                trans.Abort();
            }
        }
    }
}

4.4. Compile Program

In Visual Studio 2022, click Build → Rebuild Solution to generate 'Addline.dll ' file.

And AddLine.dll will be generated in the path 'C:\Sample\dotNet\AddLine\bin\Debug\net8.0 '(the path can be set).

4.5. Run Program

Run GstarCAD and input ' netload ' at command line to launch Select .Net Assembly dialog window, select the 'AddLine.dll ' and click Open button to load it.

Input 'AddLine ' at command line, there will be a straight line generated.

5. Visual Studio 2022 VB .NET Programming Sample

The following is an example of how to create a project called ' vbAddLine ', assuming that the GstarCAD SDK is installed in the ' C:\grxsdk '.

• 5.1. Create .NET project

• 5.1.1. Run Microsoft® Visual Studio 2022

Click File → New → Project to launch the New Project dialog window. Select Visual Basic in the drop down list on the right side and click Class Library from the list frame.

5.1.2. Input Project Save Path and Project Name

Input ' vbAddLine ' at the Project Name field in the New Project dialog box, enter ' C:\Sample\dotNet ” in the Location field, and click Next . As shown below.

5.1.3. Finish Creating New Project

Select .NET 8.0 (Long Term Support) in the drop-down list and click the Create button to finish creating the new project ' AddLine '.

5.2. Set the Reference

5.2.1. Add Reference

In Visual Studio 2022, find the ' vbAddLine ' project in the Solution Explorer , right-click on it and select Add → Reference .

After the Reference Manager dialog window pops out, click Browse as shown below.

5.2.2. Choose and Add Reference File

From the GstarCAD SDK installation directory, e.g. ' C:\grxsdk' , select 'GcCoreMgd.dll', 'GcDbMgd.dll' and 'GcMgd.dll' in ' \arx\inc ' and 'GrxCAD.Interop.dll '(or ' acax.tlb ') in ' \arx\inc-x64 ', and add them by clicking Add button.

when COM is used in the program).

After adding the files, right-click added ' GcCoreMgd.dll', 'GcDbMgd.dll' and 'GcMgd.dll' files and select Properties at the context menu, the Reference Properties palette pops up. Set the value of Copy Local property to False . The following screenshot shows how to change Copy Local property of ' GcCoreMgd.dll '.

• ' GcCoreMgd.dll ' includes the following namespaces:

Gssoft.Gscad.ApplicationServices

Gssoft.Gscad.ApplicationServices.Core

Gssoft.Gscad.EditorInput

Gssoft.Gscad.GraphicsSystem

Gssoft.Gscad.Internal

Gssoft.Gscad.PAL.FontUtils

Gssoft.Gscad.PlottingServices

Gssoft.Gscad.Publishing

Gssoft.Gscad.Runtime

Gssoft.Gscad.Windows

 ' GcDbMgd.dll ' includes the following namespaces: Gssoft.Gscad Gssoft.Gscad.Colors Gssoft.Gscad.ComponentModel Gssoft.Gscad.DatabaseServices Gssoft.Gscad.DatabaseServices.Filters Gssoft.Gscad.DatabaseServices.Internal Gssoft.Gscad.Geometry Gssoft.Gscad.GraphicsInterface Gssoft.Gscad.GraphicsSystem Gssoft.Gscad.Internal Gssoft.Gscad.LayerManager Gssoft.Gscad.PAL.FontUtils Gssoft.Gscad.Runtime

 'GcMgd.dll' includes the following namespaces: Gssoft.Gscad.ApplicationServices Gssoft.Gscad.EditorInput Gssoft.Gscad.Internal Gssoft.Gscad.Internal.Calculator Gssoft.Gscad.Internal.DatabaseServices Gssoft.Gscad.Internal.Forms Gssoft.Gscad.Internal.PreviousInput Gssoft.Gscad.Internal.PropertyInspector Gssoft.Gscad.Internal.Reactors Gssoft.Gscad.Internal.Render.RapidRT Gssoft.Gscad.Internal.Windows Gssoft.Gscad.PAL.FontUtils Gssoft.Gscad.Windows Gssoft.Gscad.Windows.Data Gssoft.Gscad.Windows.Data.Render.RapidRT Gssoft.Gscad.Windows.ToolPalette

• ' GrxCAD.Interop.dll ' shows the corresponding .NET APIs of COM.

5.3. Add code

Add the following codes to 'Class1.vb':

Imports Gssoft.Gscad.ApplicationServices
Imports Gssoft.Gscad.DatabaseServices
Imports Gssoft.Gscad.Geometry
Imports Gssoft.Gscad.Runtime

Public Class Class1
    <CommandMethod("vbAddLine")>
    Public Sub vbAddLine()
        Dim startpt As New Point3d(4.0, 2.0, 0.0)
        Dim endpt As New Point3d(10.0, 7.0, 0.0)
        Dim pLine As New Line(startpt, endpt)
        Dim lineid As ObjectId
        Dim db As Database = Application.DocumentManager.MdiActiveDocument.Database
        Dim tm As Gssoft.Gscad.DatabaseServices.TransactionManager = db.TransactionManager
        Dim ta As Transaction = tm.StartTransaction()
        Try
            Dim bt As BlockTable = tm.GetObject(db.BlockTableId, OpenMode.ForRead, False)
            Dim btr As BlockTableRecord = tm.GetObject(bt(BlockTableRecord.ModelSpace),
OpenMode.ForWrite, False)
            lineid = btr.AppendEntity(pLine)
            tm.AddNewlyCreatedDBObject(pLine, True)
            ta.Commit()
        Finally
            ta.Dispose()
        End Try
    End Sub
End Class

5.4. Compile Program

In Visual Studio 2022, click Build→Rebuild Solution to generate 'Addline.dll' file.

And AddLine.dll will be generated in the path 'C:\Sample\dotNet\vbAddLine\bin\Debug\net8.0 '(the path can be set).

5.5. Run Program

Run GstarCAD and input 'netload' at command line to launch Select .Net Assembly dialog window, select the 'vbAddLine.dll' and

click Open button to load it.

Figure 5.9

6. C# .NET and VB .NET Namespace Modification

 VB .NET:

Change 'Autodesk.AutoCAD ' to 'Gssoft.Gscad ' after the 'Imports '

• C# .NET:

Change 'Autodesk.AutoCAD ' to 'Gssoft.Gscad ' after the 'using '

• COM With VB .NET:

Add 'Imports GcadVbaLib ' and delete 'Autodesk.AutoCAD.Interop.Common '

• COM With C# .NET:

Add 'using GcadVbaLib ' and delete 'Autodesk.AutoCAD.Interop.Common '

For the COM object name in the codes, such as AcadLWPolyline, it is needed to change the prefix ' Acad' to ' Gcad' , e.g. 'AcadLWPolyline ' should be change to 'GcadLWPolyline '.

If it's not sure a COM object exists or not, then first check it from the object browser, e.g. for ACAD_COLOR , check whether there is corresponding GCAD_COLOR first from the browser. Then change ' ACAD_COLOR' to ' GCAD_COLOR' if GCAD_COLOR is found.

7. Copyright

Copyright reserved: Gstarsoft Co.,Ltd

Copying and referencing any part of this document is allowed. No part of this document may be changed without permission. Please keep this statement when copying or referencing this document.