Any ideas why on some links that I try to access using HttpWebRequest I am getting "The remote server returned an error: (304) Not Modified." in the code?
The code I'm using is from Jeff's post here (the page seems to have disappeared, see an archive copy at the Wayback Machine).
Note the concept of the code is a simple proxy server, so I'm pointing my browser at this locally running piece of code, which gets my browsers request, and then proxies it on by creating a new HttpWebRequest, as you'll see in the code. It works great for most sites/links, but for some this error comes up. You will see one key bit in the code is where it seems to copy the http header settings from the browser request to it's request out to the site, and it copies in the header attributes. Not sure if the issue is something to do with how it mimics this aspect of the request and then what happens as the result comes back?
case "If-Modified-Since":
request.IfModifiedSince = DateTime.Parse(listenerContext.Request.Headers[key]);
break;
I get the issue for example from http://en.wikipedia.org/wiki/Main_Page
PS. UPDATE HERE
Still can't work this out. Basically I can identify 1 link which has an issue, and it seems to work fine, 2nd time it gets the error, 3rd time OK, 4th time gets the error, 5th time OK etc. As if there is some state not getting cleared or something in the code. I've tried to clean up the code a bit using "using" type statements etc.
Here's the code. If anyone can spot why every 2nd time I browse to a link like http httpwebrequest http-status-code-304 if-modified-since