Filter for elements where parameter unequal to string

[m.mastbergen]

I want to get each element that does not yet have "theValue" for a specific parameter. In the following code example i filter for elements that DO have the value, how do i reverse/invert this to get what i need?

FilteredElementCollector fec = new FilteredElementCollector(doc);
var elements = fec.ToElements();           
var id = elements[0].LookupParameter("IfcName").Id;
ParameterValueProvider pvp = new ParameterValueProvider(id);            
var fsc = new FilterStringEquals();            
var ruleValue = "theValue";           
var frule = new FilterStringRule(pvp, fsc, ruleValue, false);            
var filter = new ElementParameterFilter(frule);            
fec = fec.WherePasses(filter);

[naveen.kumar.t · Accepted solution]

Hi @m.mastbergen ,

You can use the FilterInverseRule

https://www.revitapidocs.com/2023/bd21b884-c026-5a16-4470-72172b71db4a.htm

Here is the sample code

https://spiderinnet.typepad.com/blog/2011/07/elementparameterfilter-using-filterinverserule-to-filte...