Question

Could someone help me out, to why my listbox is empty?

The XmlDocument contains the following XML:

<Config>
  <Tabs>
    <Tab Name="Test1" />
    <Tab Name="Test2" />
  </Tabs>
</Config>

In my XAML file I have tried the following

<Window>
  <Grid>
     <ListBox DataContext="{Binding {StaticResource Data}, XPath=//Tabs}" ItemsSource="{Binding XPath=Tab/@Name}">
     </ListBox>
  </Grid>
<Window>

I know I haven’t set up the binding to name attribute but shouldn’t this display XmlDocument.XmlNode.ToString() for each Tab Node if it was working?

My C# Constructor Code behind:

InitializeComponent();
this.doc = new XmlDocument();
doc.LoadXml(config.document.OuterXml);
XmlDataProvider provider = (XmlDataProvider)Resources["Data"];
provider.Document = doc;
provider.Refresh();

With config.document.OuterXml being a valid document containing the above xml.

I got this working with procedural code using Collections, but I have been trying to figure out how to bind directly to XML.

Update: ListBox empty

Now there is no binding errors, but my listbox is coming up empty, I have double checked my XML file, and even did MessageBox.Show(provider.Document.OuterXML) and can confirm that the XmlDocument does have the correct nodes.

Thanks in advance

Answer 1

If you set the XmlDataProvider‘s Document property to your XmlDocument, it will refresh the bindings any time the XmlNode.NodeChanged event is raised. Since Document isn’t a dependency property, you can’t bind to it, so you have to set it in code; this should do the trick:

In your XAML:

<Window.Resources>
   <XmlDataProvider x:Key="Data"/>
</Window.Resources>

...

<ListBox 
    DataContext="{Binding {StaticResource Data}, XPath=Config/Tabs}"
    ItemsSource="{Binding XPath=Tab/@Name}"/>

In the window’s constructor:

InitializeComponent();
XmlDocument d = new XmlDocument();
d.Load("MyData.xml");
XmlDataProvider p = (XmlDataProvider)Resources["Data"];
p.Document = d;

Now any changes you make to your XmlDocument will be reflected in the ListBox.

Edit:

I can’t tell you what you’re doing wrong, but perhaps you’ll be able to when you compare what you’re doing with the below, which is a complete working example.

Window1.xaml:

<Window x:Class="Test.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Window1">
    <Window.Resources>
        <XmlDataProvider x:Key="Data"/>
    </Window.Resources>
    <ListBox 
        DataContext="{Binding Source={StaticResource Data}, XPath=Config}" 
        ItemsSource="{Binding XPath=Tabs/Tab/@Name}"/>     
</Window>

Window1.xaml.cs:

using System.Windows;
using System.Windows.Data;
using System.Xml;

namespace Test
{
    public partial class Window1 : Window
    {
        public Window1()
        {
            InitializeComponent();

            XmlDocument d = new XmlDocument();
            string xml = @"<Config><Tabs><Tab Name='foo'/><Tab Name='bar'/></Tabs></Config>";
            d.LoadXml(xml);
            ((XmlDataProvider) Resources["Data"]).Document = d;
        }
    }
}