Binding to WPF Treeview templated item

I've got a TreeView whose data context is set using

        LayoutRoot.DataContext = value

from the code-behind.

CommandTreeViewModel has an Commands property of IEnumerable(Of CommandViewModel)

CommandViewModel in turn has multiple children of CommandViewModel

In My XAML, I convert this into tree items using the following XAML

        <TreeView ItemsSource="{Binding}"
                  DataContext="{Binding FirstGeneration}"
                  x:Name="CommandTreeView">
            <TreeView.ItemTemplate>
                <HierarchicalDataTemplate ItemsSource="{Binding Children}">
                    <Border BorderThickness="1"
                            Width="200"
                            Margin="2"
                            CornerRadius="10,0,10,0">
                        <StackPanel Orientation="Horizontal"
                                <Image Source="{Binding Icon}"
                                       Width="24"
                                       Height="24" />
                            <TextBlock VerticalAlignment="Center"
                                       FontSize="13"
                                       Margin="10,0,0,0"
                                       Text="{Binding Name}"
                                       Foreground="White" />
                        </StackPanel>
                    </Border>
                </HierarchicalDataTemplate>
            </TreeView.ItemTemplate>

Now I've got an image and two textblocks elsewhere which I want to bind to elements on the original datasource for the selected treeview item - specifically, Icon, Description, Name. I'm attempting to bind them as shown below:

            <StackPanel Orientation="Vertical"
                DataContext="{Binding ElementName=CommandTreeView, Path=SelectedItem}">
                <Image x:Name="CommandIcon"
                       Width="64"
                       Height="64"
                       Source="{Binding XPath=@Icon}"></Image>
            </StackPanel>

and the same with the TextBlocks 's Text property.

I'm getting the following exception in the output window when I click on a treeview item...

System.Windows.Data Error: 44 : BindingExpression with XPath cannot bind to non-XML object.; XPath='@Icon' BindingExpression:Path=/InnerText; DataItem='CommandViewModel' (HashCode=39320280); target element is 'Image' (Name='CommandIcon'); target property is 'So开发者_JAVA技巧urce' (type 'ImageSource') CommandViewModel:'BitBox.Core.CommandViewModel'
System.Windows.Data Error: 44 : BindingExpression with XPath cannot bind to non-XML object.; XPath='@Name' BindingExpression:Path=/InnerText; DataItem='CommandViewModel' (HashCode=39320280); target element is 'TextBlock' (Name='CommandTitle'); target property is 'Text' (type 'String') CommandViewModel:'BitBox.Core.CommandViewModel'
System.Windows.Data Error: 44 : BindingExpression with XPath cannot bind to non-XML object.; XPath='@Description' BindingExpression:Path=/InnerText; DataItem='CommandViewModel' (HashCode=39320280); target element is 'TextBlock' (Name='CommandBody'); target property is 'Text' (type 'String') CommandViewModel:'BitBox.Core.CommandViewModel'

Your XAML uses an XPath in the binding which is only used when binding to an XML document:

{Binding XPath=@Icon}

Try this instead:

{Binding Path=Icon}

There could be something else going on as well.

Do you build your CommandViewModel hierarchy based on some XML? Because if that is the case your CommandViewModel should also have a property like XmlNode SourceNode that links to the corresponding XmlNode and then in your XAML you should do:

       <StackPanel Orientation="Vertical"
            DataContext="{Binding ElementName=CommandTreeView, Path=SelectedItem.SourceNode}">
            <Image x:Name="CommandIcon"
                   Width="64"
                   Height="64"
                   Source="{Binding XPath=@Icon}"></Image>
        </StackPanel>

then it should work.

Or if you don't use XML at all, do as StellarEleven suggested - remove the "X" and "@" from {Binding XPath=@Icon}.