Execuse me, what is the meaning of the code below?
[Autodesk.Revit.Attributes.Transaction(Autodesk.Revit.Attributes.TransactionMode.Manual)]
These are codes of "Hello Revit" API.
problem about the API code
That specifies whether your add-in is read-only or not.
There used to be a third option for 'automatic', but that has been removed:
http://thebuildingcoder.typepad.com/blog/2012/05/read-only-and-automatic-transaction-modes.html
http://thebuildingcoder.typepad.com/blog/2016/04/whats-new-in-the-revit-2017-api.html#2.3
http://thebuildingcoder.typepad.com/blog/2016/05/the-building-coder-samples-2017.html#4
By the way, your code snippet is much more useful if you include it as text instead of a screen snapshot.
The latter has lots of disadvantages, e.g., is harder to read, will not be included and analysed by searches and cannot be copied and pasted.
Cheers,
Jeremy
Accepted solution
Please read the getting started material:
http://thebuildingcoder.typepad.com/blog/about-the-author.html#2
That will tell you all you need.
Specifically:
Furthermore, please always perform at least a minimal search of your own before raising a question here and causing useless effort for your peers.
Thank you.
Cheers,
Jeremy