Question

I want to get Network Interface on which HttpWebRequest was made

I found WebRequestExtensions.GetCurrentNetworkInterface function for this. HttpWebRequest also has GetCurrentNetworkInterface() method to perform the same.

This is my code:

 HttpWebRequest httpWebRequest = HttpWebRequest.CreateHttp(new Uri(Url, UriKind.Absolute)); 
 //this line throws InvalidOperationException       
 NetworkInterfaceInfo i = httpWebRequest.GetCurrentNetworkInterface();

I perform method call from UI thread. If I made call after BeginGetResponse exception tells “request was finished”. What is workaround for this?

Exception info:

Message is InvalidOperationException

StackTrace:

  at System.Net.Browser.ClientHttpWebRequest.GetConnectionDetails(IntPtr& Details, Int32& sizeofDetails)
  at Microsoft.Phone.Net.NetworkInformation.WebRequestExtensions.GetCurrentNetworkInterface(WebRequest request)

Answer 1

HttpWebRequest httpWebRequest = HttpWebRequest.CreateHttp(new Uri(Url, UriKind.Absolute));

httpWebRequest.BeginGetResponse(result =>
{
    // Handle response
}, null);

var info = WebRequestExtensions.GetCurrentNetworkInterface(httpWebRequest);

I had a similar problem recently and found you can’t call GetCurrentNetworkInterface before BeginGetResponse (because the connection hasn’t been made) but if you call it within the BeginGetResponse callback the request has already completed and you get the “Web request is already finished” error.

ADDED by question-starter:

Fully-worker code which allows to get NetworkInterfaceInfo of HttpWebRequest from background thread (used BackgroundWorker in this example to simulate this):

BackgroundWorker backgroundWorker = new BackgroundWorker();
backgroundWorker.DoWork += (s, 4) =>
{
    HttpWebRequest httpWebRequest = HttpWebRequest.CreateHttp(new Uri("http://stackoverflow.com", UriKind.Absolute));

    EventWaitHandle Wait = new AutoResetEvent(false);

    httpWebRequest.BeginGetResponse(result =>
    {
        Wait.Set();
    }, null);

    Wait.WaitOne();
    Deployment.Current.Dispatcher.BeginInvoke(() =>
    {                        
        var info = WebRequestExtensions.GetCurrentNetworkInterface(httpWebRequest);
        MessageBox.Show(info.InterfaceType.ToString());
    });
};
backgroundWorker.RunWorkerAsync();

ADDED AFTER FULL-DAY DEBUGGING:
I can’t make it work 100% time, especially when loaded page is small. In this situation “request is finished” appears all the time. But with large loaded page it works even without EventWaitHandle