topic Re: Invalid operation exception in Revit API Forum

Invalid operation exception

Mohamed.E.Salem — Mon, 01 Oct 2018 21:21:31 GMT

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

Re: Invalid operation exception

naveen.kumar.t — Wed, 03 Oct 2018 05:07:18 GMT

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

Re: Invalid operation exception

Mohamed.E.Salem — Wed, 03 Oct 2018 17:07:17 GMT

hi @naveen.kumar.t

only one object

Re: Invalid operation exception

Mohamed.E.Salem — Wed, 03 Oct 2018 18:09:19 GMT

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?

Re: Invalid operation exception

naveen.kumar.t — Thu, 04 Oct 2018 06:10:08 GMT

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

Re: Invalid operation exception

Mohamed.E.Salem — Thu, 04 Oct 2018 22:12:03 GMT

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