private static void OnColumnsPropertyChanged(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs e)
        {
            RadGridView grid = dependencyObject as RadGridView;
            INotifyCollectionChanged columns = e.NewValue as INotifyCollectionChanged;

            if (grid != null && columns != null)
            {
                MyColumnsBindingBehavior behavior = new MyColumnsBindingBehavior(grid, columns);
                behavior.Attach();
            }
        }
        private static void OnColumnsPropertyChanged(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs e)
        {
            RadGridView grid = dependencyObject as RadGridView;
            INotifyCollectionChanged columns = e.NewValue as INotifyCollectionChanged;

            if (grid != null && columns != null)
            {
                MyColumnsBindingBehavior behavior = new MyColumnsBindingBehavior(grid, columns);
                behavior.Attach();
            }
        }