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;                 }              }         }                } } 

Answer 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.