Error when submitting resultbuffer to xdata

[Anonymous]

I'm still new to AutoCAD programming.  I'm taking over some code from a developer that is no longer here.  Right now when the code saved a resultbuffer object to xdata, I get an eregappidnotfound.  Due to various forums, I believe this is because the ID is not being registered with the database before it's beign inserted.

The error is thrown on this line: XData.ToXData(partCollection);

using (Autodesk.AutoCAD.DatabaseServices.DBObject dbObj = t.GetObject(objId, Autodesk.AutoCAD.DatabaseServices.OpenMode.ForWrite))
{
     DeviceName.SetDeviceName((Autodesk.AutoCAD.DatabaseServices.BlockReference)dbObj, txtDeviceName.Text);
     dbObj.XData = XData.ToXData(partCollection);
     t.Commit();
}

 The code for the ToXData function is here: 

public static ResultBuffer ToXData(PartCollection Parts)
    {
        //Write out some header information
        ResultBuffer rb = new ResultBuffer(new TypedValue(System.Convert.ToInt32(DxfCode.ExtendedDataRegAppName), XDATA_APP_NAME), new TypedValue(System.Convert.ToInt32(DxfCode.ExtendedDataInteger16), XDATA_TYPE), new TypedValue(System.Convert.ToInt32(DxfCode.ExtendedDataInteger16), XDATA_SUBTYPE), new TypedValue(System.Convert.ToInt32(DxfCode.ExtendedDataRegAppName), XDATA_Part_NAME), new TypedValue(System.Convert.ToInt32(DxfCode.ExtendedDataInteger16), Parts.Count));

        //Write the individual Parts
        for (int i = 0; i <= Parts.Count - 1; i++)
        {
            rb.Add(new TypedValue(System.Convert.ToInt32(DxfCode.ExtendedDataRegAppName), XDATA_Part_NAME + (i + 1)));
            rb.Add(new TypedValue(System.Convert.ToInt32(DxfCode.ExtendedDataInteger16), Parts[i].Quantity));
            rb.Add(new TypedValue(System.Convert.ToInt32(DxfCode.ExtendedDataAsciiString), Parts[i].IdentNumber));
            rb.Add(new TypedValue(System.Convert.ToInt32(DxfCode.ExtendedDataAsciiString), Parts[i].Description));
            rb.Add(new TypedValue(System.Convert.ToInt32(DxfCode.ExtendedDataAsciiString), Parts[i].Location));
            rb.Add(new TypedValue((int)DxfCode.ExtendedDataAsciiString, System.ComponentModel.TypeDescriptor.GetProperties(typeof(Part))["Purchase"].Converter.ConvertToString(Parts[i].Purchase)));
            rb.Add(new TypedValue((int)DxfCode.ExtendedDataAsciiString, System.ComponentModel.TypeDescriptor.GetProperties(typeof(Part))["SpareWear"].Converter.ConvertToString(Parts[i].SpareWear)));
        }
        return rb;
    }

 I realize that's a lot of code, but in short it takes a list of Part objects, iterates through each, then adds them to a resultbuffer.  The code works when only 1 or 2 parts are in the partCollection.  If 3 or more parts are in the collection, I get the eregappidnotfound error.  

Can anyone point em in the right direction?

[Alexander.Rivilis · Accepted solution]

eregappidnotfound error means that there is no record in RegAppTable RegAppTableRecord. Check it out. If you want to add Xdata Parts [i] then RegAppTableRecord named XDATA_Part_NAME + (i + 1) should already be in RegAppTable.

[Anonymous]

Thank you.  That confirms what I had guessed. Combining your code snippet with the code from the documentation, I was able to create a working solution. Documentation code