Changing Revit BuiltInParameter when on Design Option

Question

In Revit, when changing a BuiltInParameter which is on a Design Option, it gets an error that it is read-only.

The line of code is: floor.get_Parameter(BuiltInParameter.FLOOR_HEIGHTABOVELEVEL_PARAM).Set(currentStoopHeigth - joist9Height)

there is a isReadOnly, but I do not know how to add it.

I do not know how to add isReadOnly to the line of code. I need to grab this parameter whether on Design Option or not, and change it.

Answer 1

If you are able to edit a parameter in Revit, then you should be able to edit it from the API. The Parameter.IsReadOnly is intended to let you know whether or not a parameter is editable for a given element. This should help prevent errors where you try to set the value of a parameter that cannot be edited.

Note that you cannot control Parameter.IsReadOnly property from the API since it is only a get property.

Here is a way to check if a parameter is read only:

var floorHeightAboveLevelParam = floor.get_Parameter(BuiltInParameter.FLOOR_HEIGHTABOVELEVEL_PARAM);

if (floorHeightAboveLevelParam != null && !floorHeightAboveLevelParam.IsReadOnly)
{
   floorHeightAboveLevelParam.Set(currentStoopHeigth - joist9Height);
}