HttpWebRequest on Compact Framework: The operation has timed-out
With .Net Compact Framework I developed an application that is doing a webrequest on interval bases. With the webrequest I sent data by providing some arguments inside the querystring. I am not interested in the response and therefore I did not assign the GetResponse() return value. I use the following code:
<br />
HttpWebRequest webRequest;</p>
<p>try<br />
{<br />
webRequest = WebRequest.Create("http://someurl.com/with.aspx?querystring=value");<br />
webRequest.Method = "GET";<br />
webRequest.KeepAlive = false;<br />
webRequest.GetResponse();<br />
}<br />
catch (Exception e){<br />
//Something goes wrong. Implement handling of this exception<br />
}<br />
finally {<br />
webRequest = null; //To clear up the webrequest<br />
}<br />
This code works… for only 2 times. The third time it is executed I get a: The operation has timed-out exception. It looks like the GetResponse() method keeps a connection (or socket) open which make it not possible to make new connection at the third time the method is executed. I solved this problem by assigning the GetResponse() value to a WebRequest variable and execute the Close() method inside the finally part of the try catch:
<br />
HttpWebRequest webRequest;<br />
WebResponse webResponse = null; //Need to assign this as null otherwise it does not compile<br />
try<br />
{<br />
webRequest = WebRequest.Create("http://someurl.com/with.aspx?querystring=value");<br />
webRequest.Method = "GET";<br />
webRequest.KeepAlive = false;<br />
webResponse = webRequest.GetResponse(); //Assign to webResponse<br />
}<br />
catch (Exception e){<br />
//Something goes wrong. Implement handling of this exception<br />
}<br />
finally {<br />
if(webResponse != null)<br />
{<br />
webResponse.Close(); //Close webresponse connection<br />
}</p>
<p> webResponse = null; //To clear up the webresponse<br />
webRequest = null; //To clear up the webrequest<br />
}<br />
Read more from the Uncategorized category. If you would like to leave a comment, click here: 5 Comments. or stay up to date with this post via RSS, or you can
Trackback from your site.
Social Bookmark :
Technorati,
Digg,
de.licio.us,
Yahoo,
Blinkbits,
Blogmarks,
Google,
Magnolia.
Leave a Comment
5 Comments so far
Had the same problem, and your work-around saved me. Thanks a lot. It seems as if the underlying win32 socket is not closed properly otherwise. Cheers, Édouard
You’re a genius… I searched that bloody close method in HttpWebRequest, but I did not look also into HttpWebResponse!
BTW, sometimes you get timeouts also because the server-side blocks TCP connection from the device. (Microsoft claims this is a tcpip.sys protection against DoS attacks… other people say it is an emule-rate-limiter!). You can download a patch for tcpip.sys to fix this.
Thanks!
Good god this has been bugging me for days. Thanks for documenting it. Close() completely sorts it out!
[...] [...]