Grid画边框

 public class GridHelper
    {
        //请注意：可以通过propa这个快捷方式生成下面三段代码

        public static bool GetShowBorder(DependencyObject obj)
        {
            return (bool)obj.GetValue(ShowBorderProperty);
        }

        public static void SetShowBorder(DependencyObject obj, bool value)
        {
            obj.SetValue(ShowBorderProperty, value);
        }

        public static readonly DependencyProperty ShowBorderProperty =
            DependencyProperty.RegisterAttached("ShowBorder", typeof(bool), typeof(GridHelper), new PropertyMetadata(OnShowBorderChanged));


        //这是一个事件处理程序，需要手工编写，必须是静态方法
        private static void OnShowBorderChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            var grid = d as Grid;
            if ((bool)e.OldValue)
            {
                grid.Loaded -= (s, arg) => { };
            }
            if ((bool)e.NewValue)
            {
                grid.Loaded += (s, arg) =>
                {
                    //改进后的做法，不是简单地根据行和列，而是根据Grid的顶层子控件的个数去添加边框，同时考虑合并的情况
                    var controls = grid.Children;
                    var count = controls.Count;

                    for (int i = 0; i < count; i++)
                    {
                        var item = controls[i] as FrameworkElement;
                        var border = new Border()
                        {
                            BorderBrush = new SolidColorBrush(Colors.LightGray),
                            BorderThickness = new Thickness(1)
                        };

                        var row = Grid.GetRow(item);
                        var column = Grid.GetColumn(item);
                        var rowspan = Grid.GetRowSpan(item);
                        var columnspan = Grid.GetColumnSpan(item);

                        Grid.SetRow(border, row);
                        Grid.SetColumn(border, column);
                        Grid.SetRowSpan(border, rowspan);
                        Grid.SetColumnSpan(border, columnspan);


                        grid.Children.Add(border);

                    }

                };
            }


        }

    }