public void readNews()
{
    Uri uri = new System.Uri("UrlDuRss");
    WebClient rssClient = new WebClient();
    rssClient.OpenReadCompleted += new OpenReadCompletedEventHandler(rssClient_OpenReadCompleted);
    rssClient.OpenReadAsync(uri);
    
}

void rssClient_OpenReadCompleted(object sender, OpenReadCompletedEventArgs e)
{
    try
    {
        Stream data = (Stream)e.Result;
        StreamReader reader = new StreamReader(data);
        String sBuffer = reader.ReadToEnd();
        XmlReader xmlDoc = XmlReader.Create(sBuffer);
    }
    catch (Exception ex)
    {
        HtmlPage.Window.Invoke("alert", ex.Message);
    }
}

 <TextBox x:Name="NomDuTextBox" Width="100" Height="20"/>

TimeSpan ts = Storyboard.GetCurrentTime(MonAnimation.Children[0]);
MonAnimation.Seek(ts.Add(TimeSpan.FromSeconds(5))); //Avancer de 5 secondes

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