How to change filetype association in the registry?

Question

first time posting in StackOverflow. :D I need my software to add a couple of things in the registry.

My program will use

Process.Star

Answer 1

Use the Registry class in Microsoft.Win32.

Specifically, you want the ClassesRoot property of Registry to access the HKEY_CLASSES_ROOT key (cf. Understanding MS Windows File Associations and HKEY_CLASSES_ROOT: Core Services).

using Microsoft.Win32;
Registry
    .ClassesRoot
    .CreateSubKey(".smc")
    .SetValue("", "SMC", RegistryValueKind.String);
Registry
    .ClassesRoot
    .CreateSubKey("SMC\shell\open\command")
    .SetValue("", "SMCProcessor \"%1\"", RegistryValueKind.String);

Replace "SMCProcessor \"%1\"" with the command-line path and argument specification for the program that you wish to associate with files with extension .smc.

But, instead of messing with the registry, why not just say

Process.Start("SMCProcessor blblabla.smc");