WebClient Download Failure For Certain URL

05-03-2008 5:44 AM |

I'm trying to use the WebClient to retrieve data from a page but it never works, always resulting in the error message: Download Failure.  I do have the necessary cross-domain XML files in place and I have tested using the WebClient to retrieve other files from this site with no problem.  I've been doing a lot of testing and the problem seems to be the URL, but I'm not sure how to fix that.

An example of the URL in question is: http://localhost:8080/html.ng/network=fim&size=movepre&property=foo&pagetype=bar&params.styles=html_vod&special=hlutest

However, if the URL were something like: http://localhost:8080/testdata.txt, it loads fine.

I tested this out using Apache and some rewrite rules to rewrite anything looking like the first URL or something like /foo to a static text file.  Both URLs work fine in my browser, but the first ALWAYS fails in Silverlight 2 while the second always works.

However, I did create a WinForms application and it works fine using the first URL.  So I'm not sure if this is an issue with the Silverlight WebClient or Uri class.

Any suggestions?

 

Re: WebClient Download Failure For Certain URL

05-03-2008 5:50 PM |

No good suggestion, my guess is that since you're URI doesn't have traditional query string syntax that the URI class is choking on the syntax.  That seems like a bug in Silverlight, not necessarily something for you to fix on the server.

Re: WebClient Download Failure For Certain URL

05-03-2008 5:50 PM |

No good suggestion, my guess is that since you're URI doesn't have traditional query string syntax that the URI class is choking on the syntax.  That seems like a bug in Silverlight, not necessarily something for you to fix on the server.

Re: WebClient Download Failure For Certain URL

05-03-2008 5:50 PM |

No good suggestion, my guess is that since you're URI doesn't have traditional query string syntax that the URI class is choking on the syntax.  That seems like a bug in Silverlight, not necessarily something for you to fix on the server.

Re: WebClient Download Failure For Certain URL

05-03-2008 5:50 PM |

No good suggestion, my guess is that since you're URI doesn't have traditional query string syntax that the URI class is choking on the syntax.  That seems like a bug in Silverlight, not necessarily something for you to fix on the server.

Re: WebClient Download Failure For Certain URL

05-03-2008 5:50 PM |

No good suggestion, my guess is that since you're URI doesn't have traditional query string syntax that the URI class is choking on the syntax.  That seems like a bug in Silverlight, not necessarily something for you to fix on the server.

Re: WebClient Download Failure For Certain URL

05-03-2008 5:50 PM |

No good suggestion, my guess is that since you're URI doesn't have traditional query string syntax that the URI class is choking on the syntax.  That seems like a bug in Silverlight, not necessarily something for you to fix on the server.

Re: WebClient Download Failure For Certain URL

05-03-2008 5:50 PM |

No good suggestion, my guess is that since you're URI doesn't have traditional query string syntax that the URI class is choking on the syntax.  That seems like a bug in Silverlight, not necessarily something for you to fix on the server.

Re: WebClient Download Failure For Certain URL

05-03-2008 5:50 PM |

No good suggestion, my guess is that since you're URI doesn't have traditional query string syntax that the URI class is choking on the syntax.  That seems like a bug in Silverlight, not necessarily something for you to fix on the server.

Re: WebClient Download Failure For Certain URL

05-03-2008 5:52 PM |

Sorry for the mulitple posts...the AJAX driven reply window is freaking out (and submitted the form as I typed).

 One thing you can try is to URL encode it using HtmlUtility.UrlEncode().

Re: WebClient Download Failure For Certain URL

05-03-2008 7:49 PM |

Na, no luck with that.  I guess it is a Silverlight problem as it works fine in a WinForms app.  I went ahead and posted a thread in the bug forum, hopefully it'll get some attention.  Thanks for your suggestion though.

Re: WebClient Download Failure For Certain URL

05-04-2008 2:45 AM |

brown950:

Na, no luck with that.  I guess it is a Silverlight problem as it works fine in a WinForms app.  I went ahead and posted a thread in the bug forum, hopefully it'll get some attention.  Thanks for your suggestion though.

Can you show me which code you wrote at that side?

I have tested like this and it works.

Re: WebClient Download Failure For Certain URL

05-04-2008 9:55 AM |

So, the issue is the URL I'm using.  It's not something I have control over either except in my test environment.  Below is the code from my test SL and WinForms apps.  The SL one always fails, the WinForms one works.  In my thread in the bug forum which you replied to I did detail the steps necessary to reproduce it.  You simply need to setup a server that lets you access something (in my case a static text file), using a url such as: /html.ng/network=fim&size=movepre&property=ign&pagetype=e3_video_stream&params.styles=html_vod&special=hlutest

For that I used Apache and mod_rewrite with this rule: RewriteRule ^/html\.ng/ /testdata.txt

Here's the SL code:

namespace SilverlightApplication2
{
    public partial class Page : UserControl
    {
        public Page()
        {
            InitializeComponent();
            PollServer();
        }

        private void PollServer()
        {
            WebClient request = new WebClient();
            request.DownloadStringCompleted += new DownloadStringCompletedEventHandler(request_DownloadStringCompleted);
            request.DownloadStringAsync(new Uri("http://localhost:8080/html.ng/network=fim&size=movepre&property=ign&pagetype=e3_video_stream&params.styles=html_vod&special=hlutest"));
        }

        void request_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e)
        {
            if (e.Error != null)
            {
                Status.Text = e.Error.Message;
            }
            else
            {

               Status.Text = e.Result;
            }
        }
    }
}

And the WinForms test:

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            WebClient req = new WebClient();
            req.DownloadStringCompleted += new DownloadStringCompletedEventHandler(req_DownloadStringCompleted);
            req.DownloadStringAsync(new Uri("http://localhost:8080/html.ng/network=fim&size=movepre&property=ign&pagetype=e3_video_stream&params.styles=html_vod&special=hlutest"));
        }

        void req_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e)
        {
            if (e.Error == null)
            {
                textBox1.Text = e.Result;
            }
        }
    }
}

Re: WebClient Download Failure For Certain URL

05-04-2008 10:25 PM |

brown950:

You simply need to setup a server that lets you access something (in my case a static text file), using a url such as: /html.ng/network=fim&size=movepre&property=ign&pagetype=e3_video_stream&params.styles=html_vod&special=hlutest

For that I used Apache and mod_rewrite with this rule: RewriteRule ^/html\.ng/ /testdata.txt

I don't have Apache server at my office. I will try this at my home.. I just need to put testdata.txt in htdocs folder and update the mod_rewrite? I will test and will let you know the result.

Re: WebClient Download Failure For Certain URL

05-04-2008 10:59 PM |

Yes, drop a file named "testdata.txt" into your htdocs directory and add the following to your httpd.conf.

RewriteEngine on
RewriteRule ^/html\.ng/ /testdata.txt

Re: WebClient Download Failure For Certain URL

05-05-2008 5:57 PM |

Ah, well thank you for clearing that up.  Guess I'm looking forward to beta 2 even more.

Also not allowing "&" would be problematic at least in my case.

Maybe you guys could just add a new attribute to the clientaccesspolicy.xml to disable that limitation for certain domains.