Change the reference level of a family instance

[Anonymous]

Hi,

I'm trying to change the reference level and the offset of a duct corner through the revit API.

This is what I did so far:

private void changeReferenceAndOffset(Element elem, Level lvl, double newOffset)
{
  Parameter param = elem.get_Parameter(BuiltInParameter.INSTANCE_FREE_HOST_OFFSET_PARAM);
  param.Set(newOffset);
  param = elem.get_Parameter(BuiltInParameter.FAMILY_LEVEL_PARAM);
  param.Set(lvl.Id);
}

The element and the level I send to this function are valid. The offset changes, but the reference level doesn't. Yet I'm still able to change it in the properties window in Revit.

What did I do wrong here ?

I'm using Revit 2018.2.

[aignatovich]

Hi!

Try to be more specific, e.g. Duct has ReferenceLevel property, which has setter, set it directly:

duct.ReferenceLevel = lvl;

[Anonymous]

Thanks for the quick answer 🙂

I did a lot of experiments and I can assure you that this corner is not considered as a duct but as a FamilyInstance by Revit.

Because of that, I can't use the ReferenceLevel property.

[aignatovich]

Oops, image did not load at the first look, sorry)

Your code seems to be working for family instances, that does not have any correlations with other element.

But you have duct fitting, which is connected to other elements (ducts). May be the best way in your case is just to move the entire (or may be only a part of) system using ElementTransformUtils ?

[aignatovich · Accepted solution]

Tested it within this simple case:

and simple iron python script code:

e = selection[0]

tx = Transaction(doc, "test")
tx.Start()

e.get_Parameter(BuiltInParameter.INSTANCE_FREE_HOST_OFFSET_PARAM).Set(0.5)
e.get_Parameter(BuiltInParameter.FAMILY_LEVEL_PARAM).Set(ElementId(15913))

tx.Commit()

It also works as expected, e.g. changed both family level and offset parameters... Also ducts stay connected...

[Anonymous]

I created another command to test what you did and it works ! So the problem comes from my side, I'll investigate my code again now.

Thanks again for those quick answers 🙂

[Anonymous]

My addin works now, I think I messed up the transaction which is why it wouldn't change the level.

What I did was this:

using (Transaction t = new Transaction(doc, "Change reference"))
{
  t.start();
  //loop over every FamilyInstance in selection
  t.commit();
}

Now I'm doing this:

Transaction t = new Transaction(doc, "Change reference");
t.start();
//loop over every FamilyInstance in selection
t.commit();

I don't know why exactly it wasn't working at first but it's the only thing I changed.

[Radish_G]

Hi @Anonymous,

I don't have any knowledge of programming.

Can you guys guide me to execute this program?