I have a ContextMenu like this:
the context menu has its own visual tree, try this calling this from your event handler like so :-
StackPanel stackPanel = GetStackPanelItemFromContextMenu((FrameworkElement)sender, yourStackPanel);
private StackPanel GetStackPanelItemFromContextMenu(FrameworkElement sender, StackPanel stackPanel) {
Point menuClickPoint = ((sender as FrameworkElement).Parent as ContextMenu).TranslatePoint(new Point(0, 0), stackPanel);
// get the first potential object that was hit
DependencyObject obj = stackPanel.InputHitTest(menuClickPoint) as DependencyObject;
// cycle up the tree until you hit the StackPanel
while (obj != null && !(obj is StackPanel)) {
obj = VisualTreeHelper.GetParent(obj);
}
return obj as StackPanel;
}