Forum Moderators: open
Welcome to WebmasterWorld [webmasterworld.com]!
Without intending to be flippant, the best way to be sure that no-one can see your code using view-page-source is to remove the page from your server. If the page can be rendered by a browser, its source can be displayed by that browser. There is no good way to get around this using HTTP and standard browsers.
If you wish to block certain IP addresses completely - so that they cannot access your site or a group of resources within your site at all, then that is possible. The method needed depends on what kind of server (e.g Apache, IIS, etc.) your site is hosted on.
HTH,
Jim