[v8i C#] Creating grouped holes via stdmdlbltin.dll

Unknown said:

mdlElmdscr_setProperties(myShape1.MdlElementDescrP(true), ...);

If you pass true to MdlElementDescrP you are telling the compiler that you will perform memory management in your code.  Furthermore, says VBA help: If a program tries to access any property or method of the element after calling MdlElementDescrP (True), then that method/property will raise an error saying something like "Element has not been initialized".

Hi Jon,

Many thanks for the response, unfortunately that hasn't remedied the problem.

I've tried the VBA example from your site, which works correctly. There is obviously something I'm doing incorrectly when calling from C#.

Regards, Alex

Unknown said:

Unfortunately that hasn't remedied the problem

Try adding your element to the active model, then read the new element.  Apply new properties to the read element, then rewrite it.

Set oElement = CreateXxx ()
ActiveModelReference.AddElement oElement
Set oElement = ActiveModelReference.GraphicalElementCache.GetLastValidElement
... modify element
oElement.Rewrite

Jon,

Again, your answer is greatly appreciated. Unfortunately not a fix. Are you able to compile and test the following sample?

Simply creating a shape and setting it's "Solid property".

C# Console App, 3.5 Framework.

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Runtime.InteropServices;

using BCOM = Bentley.Interop.MicroStationDGN;

using BMI = Bentley.MicroStation.InteropServices;

namespace ForumTest

{

   class Program

   {

               [DllImport("stdmdlbltin.dll")]

       static extern int mdlElmdscr_setProperties(int edP, ref int level, ref int ggNum, ref int elementClass, ref int locked, ref int newElm, ref int modified, ref int viewIndep, ref int solidHole);

       static void Main(string[] args)

       {

           int tmp = 0;

           int solid = 1;

           int hole = 0;

           BCOM.Application oApp = BMI.Utilities.ComApp;

           BCOM.DesignFile oDGN = oApp.OpenDesignFile("C:\\Data\\Blank.dgn", false);

           Console.WriteLine(oApp.Caption);

           BCOM.Point3d[] myShapeVerts = new BCOM.Point3d[5];

           myShapeVerts[0].X = 0; myShapeVerts[0].Y = 0;

           myShapeVerts[1].X = 0; myShapeVerts[1].Y = 10;

           myShapeVerts[2].X = 10; myShapeVerts[2].Y = 10;

           myShapeVerts[3].X = 10; myShapeVerts[3].Y = 0;

           myShapeVerts[4].X = 0; myShapeVerts[4].Y = 0;

           BCOM.ShapeElement myShape = oApp.CreateShapeElement1(null, myShapeVerts, BCOM.MsdFillMode.UseActive);

           int elemDescP = myShape.MdlElementDescrP(false);

           Console.Write("Element DescrP: ");

           Console.Write(Convert.ToString(elemDescP));

           mdlElmdscr_setProperties(elemDescP, ref tmp, ref tmp, ref tmp, ref tmp, ref solid, ref tmp, ref tmp, ref solid);        

           oApp.ActiveModelReference.AddElement(myShape);

           oDGN.Close();

           oApp.Quit();

       }

Unknown said:

 BCOM.ShapeElement myShape = oApp.CreateShapeElement1(null, myShapeVerts, BCOM.MsdFillMode.UseActive);

If you omit mdlElmdscr_setProperties, is your shape created correctly?  You're initialising the X,Y components of your Point3d array, but not the Z component.  Be explicit!

Jon,

Yes, bar the MDL call everything works as expected.

In the main app, Z is initialised - apologies for missing it in the snippet posted here.

Regards, Alex

Unknown said:

[DllImport("stdmdlbltin.dll")]
static extern int mdlElmdscr_setProperties(int edP, ref int level, ref int ggNum, ref int elementClass, ref int locked, ref int newElm, ref int modified, ref int viewIndep, ref int solidHole);

The function is going to change the element, which is fine in C/C++ because you're passing a pointer to the function.  But I'm not sure what C# can do with int edP, since it doesn't know about pointers.  Try declaring the function like this...

[DllImport("stdmdlbltin.dll")]
static extern int mdlElmdscr_setProperties(ref int edP, ref int level, ref int ggNum, ref int elementClass, ref int locked, ref int newElm, ref int modified, ref int viewIndep, ref int solidHole);

I have no idea whether that will work. 

Hi Alex,

Have you tried to call mdlElmdscr_createShapeWithHoles directly in your C# code ?

HTH, YongAn

Unknown said:

Have you tried to call mdlElmdscr_createShapeWithHoles directly in your C# code?

I think he's used this article about Creating a Grouped Hole with VBA as his starting point.

Today, another one asked me the same question and I found we can use ClosedElement.GetDifferenceShapes method to create a grouped hole simply.

Today, another one asked me the same question and I found we can use ClosedElement.GetDifferenceShapes method to create a grouped hole simply.