The Quick Graph component has a custom UI:
Is there publicly available code of a component with a custom UI?
The Quick Graph component has a custom UI:
Is there publicly available code of a component with a custom UI?
What do you need to know is here:
https://developer.rhino3d.com/api/grasshopper/html/8a7974ab-7b2b-4f48-84d0-6e81b184e6b0.htm
and to work with GDI+ which is the render engine:
Thank you!