Question

I need my app to perform a certain action when DataGrid is double clicked. The action should not be performed if a scrollbar is doubleclicked. So I try to see what is doubleclicked:

private void DataGrid_MouseDoubleClick(object sender, MouseButtonEventArgs e)
        {
            Point p = Mouse.GetPosition(this.DataGrid1);
            IInputElement ie = this.DataGrid1.InputHitTest(p);
        }

But when I doubleclick a scrollbar, then IInputElement appears to be all sort of stuff:
Microsoft.Windows.Themes.ScrollChrome or System.Windows.Shapes.Rectangle . So I am not sure if I clicked a scrollbar.

So how do I check if I really doubleclicked a scrollbar?

Answer 1

There’s no need to use hit test here, just check if e.OriginalSource has a parent of ScrollBar type by traversing the visual tree. There’s one potential issues with this approach – your UI element has to be loaded, which is typically the case when dealing with mouse events anyway. Heres’ the code which checks if an UIElement has a parent of a specific type.

public static T GetParentOfType<T>(DependencyObject current)
          where T : DependencyObject
        {
            for (DependencyObject parent = VisualTreeHelper.GetParent(current);
                parent != null;
                parent = VisualTreeHelper.GetParent(parent))
            {
                T result = parent as T;

                if (result != null)
                    return result;
            }

            return null;
        }