Combining ItemsControl with draggable items - Element.parent always null
Since the items are not directly inside the canvas, you need to walk up the visual tree until you find the canvas. I usually use the following extension method to do that:
public static T FindAncestor<T>(this DependencyObject obj) where T : DependencyObject{ DependencyObject tmp = VisualTreeHelper.GetParent(obj); while(tmp != null && !(tmp is T)) { tmp = VisualTreeHelper.GetParent(tmp); } return tmp as T;}Put the method above in a static class, and import the namespace where it is declared. In the DraggableExtender code, just replace this line:
Canvas canvas = element.Parent as Canvas;With this one:
Canvas canvas = element.FindAncestor<Canvas>();