Element Returns null

[mohd.fadel]

Hello,

I don't know what i'm missing here.. I'm trying to set the value of a parameter after i retrieve the element from a set of ids. However, the element is returning null and i'm a receiving an error "Object reference not set to an instance of an object"

Element elem = activeDoc.GetElement("224716") as Element;

Parameter RW_CV1 = elem.LookupParameter("RW_CV-1");
RW_CV1.Set("New");
RW_CV1.SetValueString("New");

please note that 224716 is a valid id of the element. I can double check that using select by id.

Any help is appreciated.

Mohamed.

[jeremy_tammik · Accepted solution]

So, you are saying that 224716 is the valid integer value of the element id.

That is good to know.

Please note that the string "224716" is something completely different. A string is not a number, nor an element id.

In this case, however, a string might very well be a Revit unique id.

And, lo and behold, the GetElement method provides three overloads, one taking an element id, another a string-valued unique id:

https://www.revitapidocs.com/2021.1/8760be74-50fd-6809-aec6-3cb168d03ea5.htm

To make use of your integer-valued element id, you need to convert the number (not the string) to an ElementId object and pass in that to GetElement. Since this is demonstrated in a numerous different places, I am sure you have already solved this problem yourself long before I finished typing this.

[mohd.fadel]

Thank you Jeremy. That did it.