Get a list of all the urls in a web page

What's the best way to get an array of all the URLs in a web pa开发者_C百科ge? and how would I do it?

Using HTML Agility Pack is a good way, maybe not the best as this would be subjective but I can tell you the worst and this is using regular expression to parse html (as you've tagged your question with regex I feel myself ion the obligation to point this out).

/<a href=\"([^\"]*)\">(.*)<\/a>/iU

or use this previous answer:

Regular expression for parsing links from a webpage?