How to: Load an XML File from an Arbitrary URI Location with LINQ to XML

Silverlight

The XDocument..::.Load methods that take a uri string as a parameter must reference a file that is located in the application's XAP package. If you want to download the file from some other location, follow these steps.

To configure a Silverlight Visual Studio project to run this example

In Solution Explorer, add assembly references to System.Xml.Linq.dll and System.Net.dll.

Modify your page.xaml file so that it includes the following TextBlock element:

<TextBlock x:Name ="OutputTextBlock" Canvas.Top ="10" TextWrapping="Wrap"/>

In the page.xaml source file for your application, add the following using statements (Imports in Visual Basic):

Visual Basic

Imports System.IO
Imports System.Xml.Linq
Imports System.Net

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

To load an XML file from an arbitrary URI location

Create the WebClient object, add the handler, and initiate the request. To request a resource as a stream, you must call an OpenReadAsync method overload.

Visual Basic

Dim wc As WebClient = New WebClient()
AddHandler wc.OpenReadCompleted, AddressOf wc_OpenReadCompleted
wc.OpenReadAsync(New Uri(uriString))

WebClient wc = new WebClient();
wc.OpenReadCompleted += wc_OpenReadCompleted;
wc.OpenReadAsync(new Uri(uriString));

Implement the wc_OpenReadCompleted callback function. This function does the following:

Checks the Error property for errors.
If there are no errors, gets the data stream and passes it to the XDocument's Load method overload.

Visual Basic

Private Sub wc_OpenReadCompleted(ByVal sender As Object, ByVal e As OpenReadCompletedEventArgs)
    If e.Error IsNot Nothing Then
        OutputTextBlock.Text = e.Error.Message
        Return
    End If
    Using s As Stream = e.Result
        Dim doc As XDocument = XDocument.Load(s)
        OutputTextBlock.Text = doc.ToString(SaveOptions.OmitDuplicateNamespaces)
    End Using
End Sub

private void wc_OpenReadCompleted(object sender, OpenReadCompletedEventArgs e)
{
    if (e.Error != null)
    {
        OutputTextBlock.Text = e.Error.Message;
        return;
    }
    using (Stream s = e.Result)
    {
        XDocument doc = XDocument.Load(s);
        OutputTextBlock.Text = doc.ToString(SaveOptions.OmitDuplicateNamespaces);
    }
}

To configure a Silverlight Visual Studio project to run this example

To load an XML file from an arbitrary URI location

Tasks

Concepts

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