How can I get the thumbnail of dwg file without open it, I want to show the thumbnail in a dialogbox.
I have read a lot of posts, but they were so many years ago, such as :
http://smartsnipp.ecomparefiles.com/code/c_sharp_windows_application/autocad_dwg_thumbnail_viewer_in...
and
https://www.theswamp.org/index.php?topic=45598.0
I am now working with AutoCad 2021, from these posts, It seems that I should know the dwg file structure(where the thumbnail save , how many bytes it takes...)，where I can get the reference document about the structure of dwg file?or any sample code with later version of autocad.
