CODEWITHSUNDEEP
c#streamwebclient
VoodooChild
VoodooChild

Reputation: 9784

webclient error (random and very very annoying)

WebClient wc = new WebClient();
wc.OpenReadCompleted += new OpenReadCompletedEventHandler(wc_OpenReadCompleted);
wc.OpenReadAsync(new Uri(url, UriKind.RelativeOrAbsolute));


void wc_OpenReadCompleted(object sender, OpenReadCompletedEventArgs e)
{ 
  if (e.Error != null || e.Cancelled)
  {
    //randomly, this code gets hit and 
    //there is no inner exception - just says "an exception occurred during a webclient request"

The error described in code happens randomly and if the same webclient request is made after that it works. Or if a new resource request is made the old one which got an error now comes before the new request......

This is very strange, any gurus here have a clue why it might be?

EDIT: information on error

System.Net.WebException: An exception occurred during a WebClient request. ---> System.Exception ---> System.Exception: Error HRESULT E_FAIL has been returned from a call to a COM component. at System.Net.BrowserHttpWebRequest.InternalEndGetResponse(IAsyncResult asyncResult) at System.Net.BrowserHttpWebRequest.<>c_DisplayClass5.b_4(Object sendState) at System.Net.AsyncHelper.<>c_DisplayClass2.b_0(Object sendState) --- End of inner exception stack trace --- at System.Net.AsyncHelper.BeginOnUI(SendOrPostCallback beginMethod, Object state) at System.Net.BrowserHttpWebRequest.EndGetResponse(IAsyncResult asyncResult) at System.Net.WebClient.GetWebResponse(WebRequest request, IAsyncResult result) at System.Net.WebClient.OpenReadAsyncCallback(IAsyncResult result) --- End of inner exception stack trace ---

The URL is a simple string having count of no more than 200.

Upvotes: 2

Views: 2720

Answers (3)

Grigory
Grigory

Reputation: 1922

Probably URL is very long. I've same issue on WP8 with 2900 symbols length URL

Upvotes: 0

Mike Caron
Mike Caron

Reputation: 14561

I am going to hazard a guess that it's timing out. I am also going to further guess that it may be a DNS issue.

It's possible that the DNS is timing out. This would be consistent with you not seeing the request in Fiddler.

I suppose it's not impossible that the request would then be filled later when you try again, and this time the DNS works. Maybe. This point I'm a bit fuzzy on, but whatever.

If you use a URL with an IP address instead of a domain name, do you still have the same problem?

Upvotes: 0

Robert MacLean
Robert MacLean

Reputation: 39261

That code would be hit if cancelled or error being generated. I suspect you are hitting a networking issue, so I would fire up Fiddler and watch the HTTP requests and make sure you are getting them back correctly.

Upvotes: 2

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