How to create Acad Proxy Entity in Autocad.net 2007?

Question

i have a proxy object like this

But i don't know how to create the same with C# (autocad.net)

Answer 1

Proxy objects are entities created in a vertical of AutoCAD that you're not currently using. Your copy of AutoCAD knows how to display it but can't modify it.

To recreate the proxy object you're showing in your post, you'll have to figure out what made the entity (AutoCAD Civil, Map, Mechanical, etc.). Once you know the true object type then you can work on recreating it properly.