HttpWebRequest BeginGetResponse callback not firing on WP8 (working on WP7)

问题

I'm having a problem with a previous app not working on WP8, which works perfectly on WP7.

This is the code I'm using for the http request:

public void SendMessage()
    {    
        request = WebRequest.Create(uri) as HttpWebRequest;
        request.Method = "POST";
        request.AllowReadStreamBuffering = true;
        request.ContentType = "application/octet-stream";

        try 
        {
            // get device info
            String deviceInfo = String.Format("platform,{0};os,{1};width,{2};height,{3};dpi,{4};",
                Config.PLATFORM_NAME,
                Environment.OSVersion.Version.ToString(),
                System.Windows.Application.Current.Host.Content.ActualWidth.ToString(),
                System.Windows.Application.Current.Host.Content.ActualHeight.ToString(),
                96);
            request.Headers["X_MX_DEVICE_INFO"] = deviceInfo;
        } 
        catch (Exception) {}

        request.BeginGetRequestStream(new AsyncCallback(ProcessRequestStream), null);
    }

    private void ProcessRequestStream(IAsyncResult asyncResult)
    {
        if (!message.IsCancelled())
        {
            try
            {
                using (Stream stream = request.EndGetRequestStream(asyncResult))
                {
                    message.GetRequest(stream);
                }
                request.BeginGetResponse(new AsyncCallback(ProcessResponseStream), null);
            }
            catch (Exception e)
            {
                syncContext.Post(OnEnd, e);
            }
        }
        else
        {
            syncContext.Post(OnEnd, null);
        }
    }

    private void ProcessResponseStream(IAsyncResult asyncResult)
    {
        if (!message.IsCancelled())
        {
            try
            {
                response = (HttpWebResponse)request.EndGetResponse(asyncResult);
                if (HttpStatusCode.OK != response.StatusCode)
                {
                    throw new Exception("http status error: " + response.ToString());
                }

                syncContext.Post(SetResponse, response);
            }
            catch (Exception e)
            {
                syncContext.Post(OnEnd, e);
            }
        }
        else
        {
            syncContext.Post(OnEnd, null);
        }
    }

    private void SetResponse(object state)
    {
        Exception ex = null;
        try
        {
            using (Stream stream = ((HttpWebResponse)state).GetResponseStream())
            {
                message.SetRespone(stream);
            }
        }
        catch (Exception e)
        {
            ex = e;
        }
        syncContext.Post(OnEnd, ex);
    }

    private void OnEnd(object state)
    {
        message.OnEnd((Exception)state);
    }
}

It looks as though BeginGetResponse's callback isn't being fired. I've tried Fiddler to see what response is coming back, and looks as though nothing is even coming back, but just for WP8.

Any possible reasons for this?

回答1:

I believe this could be related to the Referer issue on Windows Phone 8.

For WP7.1: The value of the Referer header is null by default. You can specify a custom value for the Referer header.

For WP8: The value of the Referer header references the installation directory of the app in the format file:///Applications/Install//Install/.

There are some blog posts around the internet, with possible solutions:

http://geoffwebbercross.blogspot.nl/2012/01/wp7-http-using-sockets-problem-with.html
http://atomaras.wordpress.com/category/windows-phone-8/

But in your case I would still strongly recommend to analyze Fiddler logs. Make sure you have downloaded and installed Fiddler4. Also, make sure you firstly launch fiddler and only then launch the WP emulator.

来源：https://stackoverflow.com/questions/15660741/httpwebrequest-begingetresponse-callback-not-firing-on-wp8-working-on-wp7

标签

silverlight

windows-phone-7

windows-phone-8

webrequest