XAML Border

Here, we will see how to create a border around XAML elements.

The Border XAML element is used to add a border around another XAML element. For example, the Canvas control in WPF does not have a border property. To place a border around an element, WPF provides the Border element. Similar to other WPF elements, the Border has Width, Height, Background and HorizontalAlignment and VerticalAlignment properties.

Besides these common properties, Border has two properties that make Border a border. These two properties are BorderThickness and BorderBrush. The BorderBrush property represents the brush that is used to draw the border. The BorderThickness property represents the thickness of the border.

The CornerRadius property represents the degree to which the corners of a Border are rounded. The following code snippet creates a Border element and sets its properties.

<Border
   BorderThickness="5"
   BorderBrush="Green"
   CornerRadius="10"
   Background="LightGray"
   HorizontalAlignment="Left"
   VerticalAlignment="Top"
   Width="270"
   Height="250" />

The code snippet in Listing 1 creates a Border around a Canvas element and sets its properties.

The output looks like in Figure 1 where all the child controls are wrapped horizontally.

<Border
   BorderThickness="5"
   BorderBrush="Green"
   CornerRadius="10"
   Background="LightGray"
   HorizontalAlignment="Left"
   VerticalAlignment="Top"
   Width="270"
   Height="250">

   <Canvas Background="LightCyan" >
      <Rectangle
         Canvas.Left="30" Canvas.Top="20"
         Height="200" Width="200"
         Stroke="Black" StrokeThickness="10" Fill="Red" />
   </Canvas>
</Border>

Listing 1

The output looks like in Figure 1 where you can see the green border with rounded corners.

Figure 1

The Border class in WPF represents a Border element. The code snippet listed in Listing 2 creates a Border, sets its properties and places it around a Canvas element.

private void CreateDynamicBorder()
{
   Border border = new Border();
   border.Background = new SolidColorBrush(Colors.LightGray);
   border.BorderThickness = new Thickness(5);
   border.BorderBrush = new SolidColorBrush(Colors.Green);
   border.CornerRadius = new CornerRadius(15);
   border.Width = 270;
   border.Height = 250;

   Canvas cnvas = new Canvas();
   Rectangle rect = new Rectangle();
   rect.Width = 200;
   rect.Height = 200;
   rect.Fill = new SolidColorBrush(Colors.Black );
   rect.StrokeThickness = 10d;
   cnvas.Children.Add(rect);
   border.Child = cnvas;
   RootLayout.Content = border;
}

Listing 2

Note. Border can have only one child element. If you need to place a border around multiple elements, you must place a border around each element.

Summary

In this article, we saw how to use the Border element to add borders to XAML elements.