How to create a custom ribbon that execute a custom action in a sharepoint library Ribbon c#?

[Joy MK]

How to create a custom ribbon that execute a custom action in a sharepoint library Ribbon programatically?

[#2]

I'm assuming that you are using Office 365 and that you will want to use CSOM:

https://lixuan0125.wordpress.com/2014/03/04/add-custom-action-through-csom-with-app/