C#（WPF）为Grid添加实线边框。

原文:C#（WPF）为Grid添加实线边框。

相信大家在做WPF项目的时候，都会用到Grid这个布局控件，一般情况下，如果只是为了布局，那就不需要显示它的边框，但是也有特殊需求，如果把它当做表格来使用，那就需要为它添加实线边框。下面帖代码：

using System.Windows;

using System.Windows.Controls;

using System.Windows.Media;

namespace WPFStart

{

    ///

    ///
为Grid添加的一个特殊功能，实线边框

    ///

    public class
GridHelper

    {

       
//边框的宽度

       
static double myBorderWidth = 1;

public static double GetBorderWidth(DependencyObject obj)

       
{

           
return (double)obj.GetValue(BorderWidthProperty);

       
}

public static void SetBorderWidth(DependencyObject obj, double
value)

       
{

           
obj.SetValue(BorderWidthProperty, value);

       
}

public static readonly DependencyProperty BorderWidthProperty
=

           
DependencyProperty.RegisterAttached("BorderWidth", typeof(double),
typeof(GridHelper), new
PropertyMetadata(OnBorderWidthChanged));

private static void OnBorderWidthChanged(DependencyObject d,
DependencyPropertyChangedEventArgs e)

       
{

           
myBorderWidth = (double)e.NewValue;

       
}

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) =>

               
{

                   
//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 row = Grid.GetRow(item);

                       
var column = Grid.GetColumn(item);

                       
var rowspan = Grid.GetRowSpan(item);

                       
var columnspan = Grid.GetColumnSpan(item);

//设置边框线的颜色

                       
var border = new Border();

                       
border.BorderBrush = new SolidColorBrush(Colors.White);

if (row == grid.RowDefinitions.Count - 1 && column ==
grid.ColumnDefinitions.Count - 1)

                           
border.BorderThickness = new Thickness(myBorderWidth);

                       
else if (row == grid.RowDefinitions.Count - 1)

                           
border.BorderThickness = new Thickness(myBorderWidth,
myBorderWidth, 0, 0);

                       
else if (column == grid.ColumnDefinitions.Count - 1)

                           
border.BorderThickness = new Thickness(myBorderWidth,
myBorderWidth, myBorderWidth, 0);

                       
else

                           
border.BorderThickness = new Thickness(myBorderWidth,
myBorderWidth,0, 0 );

Grid.SetRow(border, row);

                       
Grid.SetColumn(border, column);

                       
Grid.SetRowSpan(border, rowspan);

                       
Grid.SetColumnSpan(border, columnspan);

                       
grid.Children.Add(border);

                   
}

               
};

           
}

       
}

    }

}

在项目中新建这个类，在XAML页面引用设置属性时，需要添加
“xmlns:ext="clr-namespace:WPFGrid（项目名称）"“，“
ext:GridHelper.ShowBorder="true"”这里就是设置边框是否显示了。

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