Hi everyone,

I’m trying to attach a .dgn file to the active DraftSight document using the following function.
However, the InsertDgn() method always returns null, and I’m not sure what I’m missing.

Here’s my code:

public static void Attach_dgn(Document dsDoc, string dngFileName)
{
    if (dsDoc == null)
    {
        MessageBox.Show("There are no open documents in DraftSight.");
        return;
    }

    if (!File.Exists(dngFileName))
    {
        MessageBox.Show("File not found: " + dngFileName);
        return;
    }

    try
    {
        Model dsModel = dsDoc.GetModel();
        SketchManager dsSketchManager = dsModel.GetSketchManager();
        dsModel.Activate();
        DgnReference dsReference = dsSketchManager.InsertDgn(dngFileName, "Model", dsDgnConversionUnitType_e.dsDgnConversionUnitType_MasterUnit, 0, 0, 0, 10, 0);


        if (dsReference == null)
        {
            MessageBox.Show("Failed to insert DGN. Check model name or file format.");
        }
        else
        {
            MessageBox.Show("DGN reference inserted successfully!");
        }
    }
    catch (COMException comEx)
    {
        MessageBox.Show("COM error: " + comEx.Message);
    }
    catch (Exception ex)
    {
        MessageBox.Show("Error: " + ex.Message);
    }
}

I’ve verified that:

• The .dgn file exists and opens fine in DraftSight.
• The file path is correct and absolute.
• I’m running this on a valid Document and SketchManager.

Still, InsertDgn() returns null every time.

Has anyone successfully used InsertDgn() through the DraftSight API?

Any guidance or working example would be greatly appreciated!