Brushes: As you learn in my
previous article part 1, part 2, part 3, part 4, part 5 a brush is used to describe the background of a button, the
foreground of text, and the fill of a shape and all brushes classes are inherit from System.Windows.Media.Brush and give you
more exotic effects.
Here we discuss about the third
Brush class that is VisualBrush.
VisualBrush: A
VisualBrush paints an area with a
Visual. It is an unusual brush that allows you to take the visual content of
an element and use it to fill any surface. Like using a VisualBrush you could
copy the appearance of a button in a window to a region somewhere else in that
same window. However, the button copy won't be clickable or interactive in any
way. A
VisualBrush also enables you to project content from one portion of your
application into another area; it's very useful for creating reflection effects
and magnifying portions of the screen.
Example of an VisualBrush
Xaml Code
<Window
x:Class="MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow"
Height="350"
Width="525">
<Rectangle
Width="150"
Height="150">
<Rectangle.Fill>
<VisualBrush
TileMode="Tile">
<VisualBrush.Visual>
<StackPanel>
<StackPanel.Background>
<DrawingBrush>
<DrawingBrush.Drawing>
<GeometryDrawing>
<GeometryDrawing.Brush>
<RadialGradientBrush>
<GradientStop
Color="Blue"
Offset="0.1"
/>
<GradientStop
Color="Green"
Offset="1.0"
/>
</RadialGradientBrush>
</GeometryDrawing.Brush>
<GeometryDrawing.Geometry>
<GeometryGroup>
<RectangleGeometry
Rect="0,0,50,50"
/>
<RectangleGeometry
Rect="50,50,50,50"
/>
</GeometryGroup>
</GeometryDrawing.Geometry>
</GeometryDrawing>
</DrawingBrush.Drawing>
</DrawingBrush>
</StackPanel.Background>
<TextBlock
FontSize="10pt"
Margin="10">MANISH</TextBlock>
</StackPanel>
</VisualBrush.Visual>
</VisualBrush>
</Rectangle.Fill>
</Rectangle>
</Window>
VB Code
Dim Rectangle6 As New Rectangle()
Rectangle6.Width = 150
Rectangle6.Height = 150
' Create a VisualBrush and use it
' to paint the rectangle.
Dim Brush As New VisualBrush()
'
' Create the brush's contents.
'
Dim Panel As New StackPanel()
' Create a DrawingBrush and use it to
' paint the panel.
Dim myBrush
As New
DrawingBrush()
Dim myGroup As New GeometryGroup()
myGroup.Children.Add(New RectangleGeometry(New
Rect(0, 0, 50, 50)))
myGroup.Children.Add(New RectangleGeometry(New
Rect(50, 50, 50, 50)))
Dim checkerBrush As New
RadialGradientBrush()
checkerBrush.GradientStops.Add(New
GradientStop(Colors.Blue, 0.1))
checkerBrush.GradientStops.Add(New
GradientStop(Colors.green, 1.0))
Dim checkers As New GeometryDrawing(checkerBrush,
Nothing, myGroup)
myBrush.Drawing = checkers
aPanel.Background = myDrawingBrushBrush
' Create some text.
Dim someText
As New
TextBlock()
someText.Text = "Hello, World"
Dim fSizeConverter
As New
FontSizeConverter()
someText.FontSize = CDbl(fSizeConverter.ConvertFromString("10pt"))
someText.Margin = New
Thickness(10)
aPanel.Children.Add(someText)
myBrush.Visual = aPanel
Rectangle6.Fill = myBrush
Output Window
Conclusion
Hope this article will help you
understand the working of VisualBrush in WPF.