Question

I am working on a genealogy application and I plan to store references to each family member in an XML document. I would like to read this document and display it as a treeview in my application and then use it to display a family member elsewhere in the application. What I need to do is find a specific value in the node tree (each member will have a unique value). How would I find this value? Could you please give me a hand here, I am quite new to node editing. TY.

BTW, below is my XAML code:

        <HierarchicalDataTemplate x:Key="NodeTemplate">
        <HierarchicalDataTemplate.ItemsSource>
            <Binding XPath="child::*" />
        </HierarchicalDataTemplate.ItemsSource>
        <TextBlock Text="{Binding Path=Name}" />
    </HierarchicalDataTemplate>
    <XmlDataProvider x:Key="xmlDataProvider"></XmlDataProvider>
</Window.Resources>
<Grid>
    <TreeView Margin="0,24,0,143"
              Name="treeView1"
              Background="AliceBlue"
              ItemsSource="{Binding Source={StaticResource xmlDataProvider}, XPath=*}"
              ItemTemplate= "{StaticResource NodeTemplate}"/>

Answer 1

I’ve assumed that the unique value is the id attribute. So the code will look so:

    private void Button_Click(object sender, RoutedEventArgs e)
    {
        var item = FindItemById(treeView1.Items.Cast<XmlElement>(), "2.1");
        if (item != null)
        {
            //Do something...
            //for example, item.SetAttribute("name", "test");

            //But this code will not work if the item isn't visible
            //var container = treeView1.ItemContainerGenerator.ContainerFromItem(item);
        }
    }

    public XmlElement FindItemById(IEnumerable<XmlElement> items, string id)
    {
        foreach (var item in items)
        {
            if (item.HasAttribute("id") && item.GetAttribute("id") == id)
                return item;
            var childItemsResult = FindItemById(item.ChildNodes.Cast<XmlElement>(), id);
            if (childItemsResult != null)
                return childItemsResult;
        }

        return null;      
    }

If your xml file has a different attribute as an identifier, change this line accordingly: item.HasAttribute("id") && item.GetAttribute("id").

The final result will be the XmlElement object. But it isn’t easy to retrieve the container because of the algorithm of generation of treeview items. Anyway, if you have a specific question – I can help to build a correct architecture.