How to register an extension to a particular custom application programmatically? [duplicate]

Question

How to register an extension to a particular custom application programmatically?

For example, i have a custom application created using C# on Windows. How can i register a file extension so when i double click a file with this extension, it starts my custom application and then i can deal with the clicked file in my app?

I need to do this programatically during installation of the custom application.

EDIT: Duplicate here

How to associate a file extension to the current executable in C#

Answer 1

How to associate a file extension to the current executable in C#