This QuickStart describes how to create a Silverlight client that can access and display a syndication service that exposes either an RSS 2.0 or Atom 1.0 syndication feed.

This QuickStart contains the following sections:

Accessing a Syndication Feed with a Silverlight Client

Syndication items can be accessed in Silverlight by using a System.Net.WebClient object to asynchronously download and read strings using a System.Xml.XmlReader from a feed. The following example accesses a syndication feed that provides the top stories at Wired magazine. To try this example, click Click Here for the Feed. A list of feed items appears below the button.

The following managed code in the Page.xaml (Page.xaml.cs or Page.xaml.vb) file shows how you access the syndication items from the feed. Uri identifies the address of the feed to be accessed. It points to the Wired magazine syndication feed.

C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using System.ServiceModel.Syndication;
using System.Xml;
using System.IO;

namespace SyndicationFeedReader
{
    public partial class Page : UserControl
    {
        public Page()
        {
            InitializeComponent();
        }
           
        void OnClick(object sender, EventArgs args)
        {
            WebClient client = new WebClient();
            client.DownloadStringAsync(
                new Uri("http://feeds.wired.com/wired/index?format=xml"));
            client.DownloadStringCompleted += 
                new DownloadStringCompletedEventHandler(request_DownloadStringCompleted);
        }

        void request_DownloadStringCompleted(object sender, 
            DownloadStringCompletedEventArgs e)
        {
            XmlReader reader = XmlReader.Create(new StringReader(e.Result));
            SyndicationFeed feed = SyndicationFeed.Load(reader);
            lbSyndicationItems.ItemsSource = feed.Items;
        }

    }
}

Visual Basic

Imports System 
Imports System.Collections.Generic 
Imports System.Linq 
Imports System.Net 
Imports System.Windows 
Imports System.Windows.Controls 
Imports System.Windows.Documents 
Imports System.Windows.Input 
Imports System.Windows.Media 
Imports System.Windows.Media.Animation 
Imports System.Windows.Shapes 
Imports System.ServiceModel.Syndication 
Imports System.Xml 
Imports System.IO 

Namespace SyndicationFeedReader 
    Public Partial Class Page 
        Inherits UserControl 
        Public Sub New() 
            InitializeComponent() 
        End Sub 
        
        Private Sub OnClick(sender As Object, args As EventArgs) 
            Dim client As New WebClient() 
            client.DownloadStringAsync(
                New Uri("http://feeds.wired.com/wired/index?format=xml")) 
            client.DownloadStringCompleted += 
                New DownloadStringCompletedEventHandler(request_DownloadStringCompleted) 
        End Sub 
        
        Private Sub request_DownloadStringCompleted(sender As Object, 
            e As DownloadStringCompletedEventArgs) 
            Dim reader As XmlReader = XmlReader.Create(New StringReader(e.Result)) 
            Dim feed As SyndicationFeed = SyndicationFeed.Load(reader) 
            lbSyndicationItems.ItemsSource = feed.Items 
        End Sub 
        
    End Class 
End Namespace 

 

Displaying a Syndication Feed

Feed tiles can be displayed by binding the titles of the feed topics to the Text property of the TextBlock.

XAML

<UserControl x:Class="SyndicationFeedReader.Page"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
    Width="600" Height="500">
    <Grid x:Name="LayoutRoot" Background="Blue">
        <Grid.RowDefinitions>
            <RowDefinition Height="100"/>
            <RowDefinition />
        </Grid.RowDefinitions>
        <Button
            Grid.Row="0"
            Margin=" 5"
            Height="60"
            Content="Click Here for the Feed"
            Click="OnClick"/>
        <ListBox x:Name="lbSyndicationItems" Margin="4" Grid.Row="1">
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <TextBlock Text="{Binding Title.Text}"/>
                </DataTemplate>
            </ListBox.ItemTemplate>>
        </ListBox>
    </Grid>
</UserControl>

The following code shows how to bind the data from the SyndicationFeed object.

C#

lbSyndicationItems.ItemsSource = feed.Items;

Visual Basic

lbSyndicationItems.ItemsSource = feed.Items 

Cross-Domain Calls

It is important to note that the call to the Wired site is a cross-domain call. It works here because the Wired feed has a cross-domain file that enables it. The cross-domain file can be accessed at Wired cross-domain file. Other feeds will have to be similarly enabled for cross-domain calls if they are to be accessed in this way. For more information, see Making a Service Available Across Domain Boundaries in the Silverlight documentation on MSDN.

See Also

• WCF Syndication
• Architecture of Syndication
• How the WCF Syndication Object Model Maps to Atom and RSS
• QuickStart: LINQ to XML