C#: handling cookies in a series of HttpWebRequest and HttpWebResponse sessions28 Jun 2009
Note: This is a revamp of a post from my old blog. It was originally published on June 28, 2009.
A while back, I was working on “wrapping” and extracting data from an online database UI. In order to retrieve data, a user would submit a series of HTML forms, view the resulting map, and then see a popup with a malformed-HTML table of all the points displayed on the map. My goal was to write some C# that would submit these painful forms in various desired combinations and retrieve and parse the points.
To add insult to injury, a Fiddler run revealed that whoever wrote the UI decided to not just maintain session state, but also transfer raw data between the different UI pages using cookies and HTTP referrers with querystrings … naturally. :’(
Thankfully, C# makes this really easy to solve - you just create a cookie “jar” that carries over from HTTP session to another:
var cookieJar = new CookieContainer(); // initialize cookieJar var request=(HttpWebRequest) WebRequest.Create("http://google.com"); // create your HttpWebRequests request.CookieContainer = cookieJar; // for each HttpWebRequest you make, add cookieJar
Use the last line to apply
cookieJar to each request and you’re set!