How to read an XML file on localhost from Silverlight application?

Question

I have Vista with IIS7.

I want to create a simple Silverlight application that reads an xml file from localhost.

I created this file (which I had to copy and click "allow" as administrator):

C:\inetpub\wwwroot\data\customers.xml

and can see it when I go here in a browser:

http://localhost/data/customers.xml

But when I run the following code, I get a target invocation exception:

using System;
using System.Net;
using System.Windows.Controls;
using System.IO;

namespace TestXmlRead234
{
    public partial class MainPage : UserControl
    {
        public MainPage()
        {
            InitializeComponent();

            WebClient client = new WebClient();
            client.OpenReadAsync(new Uri("http://localhost/data/customers.xml", UriKind.Absolute));
            client.OpenReadCompleted += new OpenReadCompletedEventHandler(client_OpenReadCompleted);
        }

        void client_OpenReadCompleted(object sender, OpenReadCompletedEventArgs e)
        {
            StreamReader myReader = new StreamReader(e.Result);
            Output.Text = myReader.ReadLine();
            myReader.Close();
        }
    }
}

So I created C:\inetpub\wwwroot\crossdomainpolicy.xml:

<?xml version="1.0" encoding="utf-8"?>
<access-policy>
    <cross-domain-access>
        <policy >
            <allow-from http-request-headers="Content-Type">
                <domain uri="*"/>
            </allow-from>
            <grant-to>
                <resource path="/" include-subpaths="true"/>
            </grant-to>
        </policy>
    </cross-domain-access>
</access-policy>

But I still get the target invocation exception error.

Here is the full inner exception:

{System.Security.SecurityException ---> System.Security.SecurityException: Sicherheitsfehler bei System.Net.Browser.BrowserHttpWebRequest.InternalEndGetResponse(IAsyncResult asyncResult) bei System.Net.Browser.BrowserHttpWebRequest.<>c__DisplayClass5.b__4(Object sendState) bei System.Net.Browser.AsyncHelper.<>c__DisplayClass2.b__0(Object sendState) --- Ende der internen Ausnahmestapelüberwachung --- bei System.Net.Browser.AsyncHelper.BeginOnUI(SendOrPostCallback beginMethod, Object state) bei System.Net.Browser.BrowserHttpWebRequest.EndGetResponse(IAsyncResult asyncResult) bei System.Net.WebClient.GetWebResponse(WebRequest request, IAsyncResult result) bei System.Net.WebClient.OpenReadAsyncCallback(IAsyncResult result)}

update 1: In windows explorer, I then right clicked C:\inetpub\wwwroot\data and made IIS_USERS a co-owner of that directory. But still get the same error. :-(

update 2: also made "everyone" co-owner of C:\inetpub\wwwroot\data, same error. :-(

update 3: opened command window as administrator and executed this command: netsh http add urlacl url=http://+:80/ user=MYDOMAIN\MyUserName

What else do I have to be able to read a text file from localhost from a Silverlight application?

PRAGMATIC ANSWER:

For testing locally just publish to the temporary localhost webserver port for which you don't even need a cross-domain file, then make necessary changes when you publish live:

using System;
using System.Linq;
using System.Net;
using System.Windows.Controls;
using System.IO;
using System.Xml.Linq;

namespace TestWeb124
{
    public partial class MainPage : UserControl
    {
        public MainPage()
        {
            InitializeComponent();

            WebClient wc = new WebClient();
            wc.OpenReadAsync(new Uri("http://localhost:49512/customers.xml", UriKind.Absolute));
            wc.OpenReadCompleted += wc_OpenReadCompleted;
        }

        private void wc_OpenReadCompleted(object sender, OpenReadCompletedEventArgs e)
        {
            if (e.Error != null)
            {
                Output.Text = e.Error.Message;
                return;
            }
            using (Stream s = e.Result)
            {
                XDocument doc = XDocument.Load(s);
                Output.Text = doc.ToString(SaveOptions.OmitDuplicateNamespaces);
                var customers = from c in doc.Descendants("customer")
                                select new
                                {
                                    FirstName = c.Element("firstName").Value
                                };

                foreach (var customer in customers)
                {
                    Output.Text += customer.FirstName;
                }

            }
        }        



    }
}

Solution 1

From what I've seen, the usual behaviour is to create a webservice that can get around Silverlight's cross domain issues entirely, then have Silverlight code communicate through that web service.

Solution 2

Making a Service Available Across Domain Boundaries