Invalid operation exception

[Mohamed.E.Salem]

hi all,

 I face a problem . I tried to use bottom to select familyinstance (column ) then make some changes . the message appears. what should i do ? (Revit 2019.1)

Thank you and best regards,

Salem

[naveen.kumar.t]

Hi @Mohamed.E.Salem,

Are you trying to pick multiple objects using PickObject??

PickObject method will help to pick only single object so try using PickObjects Method.

try using below link

PickObjects

 

[Mohamed.E.Salem]

hi   @naveen.kumar.t

only one object

[Mohamed.E.Salem]

I tried to trace my code . I found that after this line

I should select the object from Revit UserInterface

but when i came back to revit I can't make any selection because the displayForm poped up

that explain null exception 

what should i do?

[naveen.kumar.t · Accepted solution]

Hi @Mohamed.E.Salem,

Try using modeless form

http://thebuildingcoder.typepad.com/blog/2011/09/modeless-forms-in-revit.html

https://forums.autodesk.com/t5/revit-api-forum/select-element-faces-using-a-form/td-p/7783748

[Mohamed.E.Salem]

Hi @naveen.kumar.t

I tried to use modeless form But i found that Revit API deals with modeless form as external application runing outside API context so i can't make transaction

what should i do ?

thank you In advance