public static void OnTextBoxPropertyChanged(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs e)
        {
            RadGridView grid = dependencyObject as RadGridView;
            TextBox     tb   = e.NewValue as TextBox;

            if (grid != null && tb != null)
            {
                CustomFilterBehavior behavior = new CustomFilterBehavior(grid, tb);
            }
        }
        public static void OnTextBoxPropertyChanged(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs e)
        {
            RadGridView grid = dependencyObject as RadGridView;
            TextBox tb = e.NewValue as TextBox;

            if (grid != null && tb != null)
            {
                CustomFilterBehavior behavior = new CustomFilterBehavior(grid, tb);
            }
        }