Posting data to webpages while keeping the sessions and cookie in c#

I'm looking for a easy way to post data to webpages while keeping the cookies. for example you login to somewhere, and late开发者_如何学Gor you do some new actions.

What's the easiest way to do that?

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There are number of ways how you can do this:

1. WebClient
2. HttpWebRequest
3. Watin
4. WebBrowser/ AxWebBrowser

The way you choose depends on your specific requirements. I prefer to use HttpWebRequest because it gives flexibility and speed.