Attach XData to project

[melanie_ernstLF68Z]

Hello!

In Civil3D it is possible to add XData to objects, but is it also possible to add it to the project?

I tried to use document.UserData, but the data is gone after the session is closed...

Thanks in advance!

[hosneyalaa]

As  @hippe013  says 

You may need to post more of your code than what you have posted. And explain what your end goal is. 

[Anton_Huizinga · Accepted solution]

You can add XData to a Layer. You can use Layer "0", it is available in every drawing and nobody can accidentally purge it.