how do I loop through all controls on a popup

Question

I'm trying to get the "PART_HeaderButton" from a DatePicker control and then apply a customized style. The problem is I can't search the visual tree to find this header button. The calendar is on a popup. It seems when the popup opens a new visual tree is created.

My question is how can I access the new generated visual tree and do my loop search?

Answer 1

private static IEnumerable<T> FindVisualChildren<T>(DependencyObject depObj) where T : DependencyObject
{
    if (depObj != null)
    {
        for (int i = 0; i < VisualTreeHelper.GetChildrenCount(depObj); i++)
        {
            DependencyObject child = VisualTreeHelper.GetChild(depObj, i);
            if (child != null && child is T)
            {
                yield return (T)child;
            }
            foreach (T childOfChild in FindVisualChildren<T>(child))
            {
                yield return childOfChild;
            }
        }
    }
}

This will return a list DependencyObjects of type that you passed as T from the object that you passed as parameter.