Question

I have many labels as children of many different stack panels which are all children of a list box, and I need to reference one of these labels were the Content.toString() == “criteria”. In other words, traversing the visual tree in WPF would be a ball ache because there are many parent/child methods to run. Is there a way of finding one of these labels on my window without it having a name and assuming I don’t know how far ‘down’ it is in the tree? Maybe there’s an item collection of everything in a window (without heirarchy) that I can run some LINQ against??

If you’re wondering why I don’t have a name for the labels – it’s because they are generated by a data template.

Thanks a lot,

Dan

Answer 1

I made a slight change to the code that @anatoliiG linked in order to return all the child controls of the specified type (instead of the first one):

private IEnumerable<childItem> FindVisualChildren<childItem>(DependencyObject obj)
    where childItem : DependencyObject
{
    for (int i = 0; i < VisualTreeHelper.GetChildrenCount(obj); i++)
    {
        DependencyObject child = VisualTreeHelper.GetChild(obj, i);

        if (child != null && child is childItem)
            yield return (childItem)child;

        foreach (var childOfChild in FindVisualChildren<childItem>(child))
            yield return childOfChild;
    }
}

With this function you could do something like this:

var criteriaLabels =
    from cl in FindVisualChildren<Label>(myListBox)
    where cl.Content.ToString() == "criteria"
    select cl;

foreach (var criteriaLabel in criteriaLabels)
{
    // do stuff...
}