asynchronous - Measuring request time in async requests -

i need run multiple web requests , measure time between request , corresponding response.

both solutions existing code using backgroundworker , new code using tpl library have following issue cannot understand:

var watch = stopwatch.startnew();  queue.enqueue(task.factory                     .fromasync<webresponse>(webrequest.begingetresponse, webrequest.endgetresponse, null)                     .continuewith(task =>                     {                         using (var response = (httpwebresponse)task.result)                         {                             // stopwatch shows wrong results                             // after multiple request watch.elapsed time arrives 10 seconds                             // wrong                             // same code running in console application works corectly                             debug.writeline("{0}\t{1}\t{2}", response.statuscode, response.contenttype, watch.elapsed);                              // lines in production wiforms app                             if (eventwebrequestfinished != null)                             {                                 // update winform gui elements (add listboc)                             }                         }                     }, 

the same issue have using datetime.now method.

if it's code, without static variables , etc., cause of problem may closure of variable 'watch'. expression gets first value of variable , next times uses value. try send variable value via 3rd parameter 'state' of fromasync method.