Cómo: Crear una reflexión

En este ejemplo se muestra cómo usar un objeto VisualBrush para crear una reflexión. Dado que VisualBrush puede mostrar un objeto visual existente, puede usar esta funcionalidad para generar efectos visuales interesantes, como reflexiones y ampliación.

Ejemplo

En el ejemplo siguiente se usa VisualBrush para crear una reflexión de un Border que contiene varios elementos. En la ilustración siguiente se muestra el resultado de aplicar este ejemplo.

Objeto visual reflejado

Objeto Visual reflejado


Imports System
Imports System.Windows
Imports System.Windows.Data
Imports System.Windows.Controls
Imports System.Windows.Media
Imports System.Windows.Media.Effects
Imports System.Windows.Media.Imaging
Imports System.IO
Imports System.Collections.ObjectModel
Imports System.Windows.Shapes
Namespace SDKSample
    Partial Public Class ReflectionExample
        Inherits Page
        Public Sub New()
            ' Create a name scope for the page.
            NameScope.SetNameScope(Me, New NameScope())

            Me.Background = Brushes.Black
            Dim myStackPanel As New StackPanel()
            myStackPanel.Margin = New Thickness(50)

            Dim myReflectedBorder As New Border()
            Me.RegisterName("ReflectedVisual", myReflectedBorder)

            ' Create a gradient background for the border.
            Dim firstStop As New GradientStop()
            firstStop.Offset = 0.0
            Dim firstStopColor As New Color()
            firstStopColor.R = 204
            firstStopColor.G = 204
            firstStopColor.B = 255
            firstStopColor.A = 255
            firstStop.Color = firstStopColor
            Dim secondStop As New GradientStop()
            secondStop.Offset = 1.0
            secondStop.Color = Colors.White

            Dim myGradientStopCollection As New GradientStopCollection()
            myGradientStopCollection.Add(firstStop)
            myGradientStopCollection.Add(secondStop)

            Dim myLinearGradientBrush As New LinearGradientBrush()
            myLinearGradientBrush.StartPoint = New Point(0, 0.5)
            myLinearGradientBrush.EndPoint = New Point(1, 0.5)
            myLinearGradientBrush.GradientStops = myGradientStopCollection

            myReflectedBorder.Background = myLinearGradientBrush

            ' Add contents to the border.
            Dim borderStackPanel As New StackPanel()
            borderStackPanel.Orientation = Orientation.Horizontal
            borderStackPanel.Margin = New Thickness(10)

            Dim myTextBlock As New TextBlock()
            myTextBlock.TextWrapping = TextWrapping.Wrap
            myTextBlock.Width = 200
            myTextBlock.Text = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit." & " Suspendisse vel ante. Donec luctus tortor sit amet est." & " Nullam pulvinar odio et wisi." & " Pellentesque quis magna. Sed pellentesque." & " Nulla euismod." & "Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas."

            borderStackPanel.Children.Add(myTextBlock)

            Dim ellipseStackPanel As New StackPanel()

            Dim ellipse1 As New Ellipse()
            ellipse1.Margin = New Thickness(10)
            ellipse1.Height = 50
            ellipse1.Width = 50
            ellipse1.Fill = Brushes.Black
            ellipseStackPanel.Children.Add(ellipse1)
            Dim ellipse2 As New Ellipse()
            ellipse2.Margin = New Thickness(10)
            ellipse2.Height = 50
            ellipse2.Width = 50
            ellipse2.Fill = Brushes.Black
            ellipseStackPanel.Children.Add(ellipse2)
            Dim ellipse3 As New Ellipse()
            ellipse3.Margin = New Thickness(10)
            ellipse3.Height = 50
            ellipse3.Width = 50
            ellipse3.Fill = Brushes.Black
            ellipseStackPanel.Children.Add(ellipse3)
            borderStackPanel.Children.Add(ellipseStackPanel)

            myReflectedBorder.Child = borderStackPanel

            ' Create divider rectangle
            Dim dividerRectangle As New Rectangle()
            dividerRectangle.Height = 1
            dividerRectangle.Fill = Brushes.Gray
            dividerRectangle.HorizontalAlignment = HorizontalAlignment.Stretch

            ' Create the object to contain the reflection.
            Dim reflectionRectangle As New Rectangle()

            ' Bind the height of the rectangle to the border height.
            Dim heightBinding As New Binding()
            heightBinding.ElementName = "ReflectedVisual"
            heightBinding.Path = New PropertyPath(Rectangle.HeightProperty)
            BindingOperations.SetBinding(reflectionRectangle, Rectangle.HeightProperty, heightBinding)

            ' Bind the width of the rectangle to the border width.
            Dim widthBinding As New Binding()
            widthBinding.ElementName = "ReflectedVisual"
            widthBinding.Path = New PropertyPath(Rectangle.WidthProperty)
            BindingOperations.SetBinding(reflectionRectangle, Rectangle.WidthProperty, widthBinding)

            ' Creates the reflection.
            Dim myVisualBrush As New VisualBrush()
            myVisualBrush.Opacity = 0.75
            myVisualBrush.Stretch = Stretch.None
            Dim reflectionBinding As New Binding()
            reflectionBinding.ElementName = "ReflectedVisual"
            BindingOperations.SetBinding(myVisualBrush, VisualBrush.VisualProperty, reflectionBinding)

            Dim myScaleTransform As New ScaleTransform()
            myScaleTransform.ScaleX = 1
            myScaleTransform.ScaleY = -1
            Dim myTranslateTransform As New TranslateTransform()
            myTranslateTransform.Y = 1

            Dim myTransformGroup As New TransformGroup()
            myTransformGroup.Children.Add(myScaleTransform)
            myTransformGroup.Children.Add(myTranslateTransform)

            myVisualBrush.RelativeTransform = myTransformGroup

            reflectionRectangle.Fill = myVisualBrush

            ' Create a gradient background for the border.
            Dim firstStop2 As New GradientStop()
            firstStop2.Offset = 0.0
            Dim c1 As New Color()
            c1.R = 0
            c1.G = 0
            c1.B = 0
            c1.A = 255
            firstStop2.Color = c1
            Dim secondStop2 As New GradientStop()
            secondStop2.Offset = 0.5
            Dim c2 As New Color()
            c2.R = 0
            c2.G = 0
            c2.B = 0
            c2.A = 51
            firstStop2.Color = c2
            Dim thirdStop As New GradientStop()
            thirdStop.Offset = 0.75
            Dim c3 As New Color()
            c3.R = 0
            c3.G = 0
            c3.B = 0
            c3.A = 0
            thirdStop.Color = c3

            Dim myGradientStopCollection2 As New GradientStopCollection()
            myGradientStopCollection2.Add(firstStop2)
            myGradientStopCollection2.Add(secondStop2)
            myGradientStopCollection2.Add(thirdStop)

            Dim myLinearGradientBrush2 As New LinearGradientBrush()
            myLinearGradientBrush2.StartPoint = New Point(0.5, 0)
            myLinearGradientBrush2.EndPoint = New Point(0.5, 1)
            myLinearGradientBrush2.GradientStops = myGradientStopCollection2

            reflectionRectangle.OpacityMask = myLinearGradientBrush2

            Dim myBlurBitmapEffect As New BlurBitmapEffect()
            myBlurBitmapEffect.Radius = 1.5

            reflectionRectangle.BitmapEffect = myBlurBitmapEffect

            myStackPanel.Children.Add(myReflectedBorder)
            myStackPanel.Children.Add(dividerRectangle)
            myStackPanel.Children.Add(reflectionRectangle)
            Me.Content = myStackPanel

        End Sub
    End Class
End Namespace
using System;
using System.Windows;
using System.Windows.Data;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Media.Effects;
using System.Windows.Media.Imaging;
using System.IO;
using System.Collections.ObjectModel;
using System.Windows.Shapes;
namespace SDKSample
{
    public partial class ReflectionExample : Page
    {
        public ReflectionExample()
        {
            // Create a name scope for the page.
            NameScope.SetNameScope(this, new NameScope());

            this.Background = Brushes.Black;
            StackPanel myStackPanel = new StackPanel();
            myStackPanel.Margin = new Thickness(50);

            Border myReflectedBorder = new Border();
            this.RegisterName("ReflectedVisual", myReflectedBorder);

            // Create a gradient background for the border.
            GradientStop firstStop = new GradientStop();
            firstStop.Offset = 0.0;
            Color firstStopColor = new Color();
            firstStopColor.R = 204;
            firstStopColor.G = 204;
            firstStopColor.B = 255;
            firstStopColor.A = 255;
            firstStop.Color = firstStopColor;
            GradientStop secondStop = new GradientStop();
            secondStop.Offset = 1.0;
            secondStop.Color = Colors.White;

            GradientStopCollection myGradientStopCollection = new GradientStopCollection();
            myGradientStopCollection.Add(firstStop);
            myGradientStopCollection.Add(secondStop);

            LinearGradientBrush myLinearGradientBrush = new LinearGradientBrush();
            myLinearGradientBrush.StartPoint = new Point(0, 0.5);
            myLinearGradientBrush.EndPoint = new Point(1, 0.5);
            myLinearGradientBrush.GradientStops = myGradientStopCollection;

            myReflectedBorder.Background = myLinearGradientBrush;

            // Add contents to the border.
            StackPanel borderStackPanel = new StackPanel();
            borderStackPanel.Orientation = Orientation.Horizontal;
            borderStackPanel.Margin = new Thickness(10);

            TextBlock myTextBlock = new TextBlock();
            myTextBlock.TextWrapping = TextWrapping.Wrap;
            myTextBlock.Width = 200;
            myTextBlock.Text = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit." +
                               " Suspendisse vel ante. Donec luctus tortor sit amet est." +
                               " Nullam pulvinar odio et wisi." +
                               " Pellentesque quis magna. Sed pellentesque." +
                               " Nulla euismod." +
                               "Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas.";

            borderStackPanel.Children.Add(myTextBlock);

            StackPanel ellipseStackPanel = new StackPanel();

            Ellipse ellipse1 = new Ellipse();
            ellipse1.Margin = new Thickness(10);
            ellipse1.Height = 50;
            ellipse1.Width = 50;
            ellipse1.Fill = Brushes.Black;
            ellipseStackPanel.Children.Add(ellipse1);
            Ellipse ellipse2 = new Ellipse();
            ellipse2.Margin = new Thickness(10);
            ellipse2.Height = 50;
            ellipse2.Width = 50;
            ellipse2.Fill = Brushes.Black;
            ellipseStackPanel.Children.Add(ellipse2);
            Ellipse ellipse3 = new Ellipse();
            ellipse3.Margin = new Thickness(10);
            ellipse3.Height = 50;
            ellipse3.Width = 50;
            ellipse3.Fill = Brushes.Black;
            ellipseStackPanel.Children.Add(ellipse3);
            borderStackPanel.Children.Add(ellipseStackPanel);

            myReflectedBorder.Child = borderStackPanel;

            // Create divider rectangle
            Rectangle dividerRectangle = new Rectangle();
            dividerRectangle.Height = 1;
            dividerRectangle.Fill = Brushes.Gray;
            dividerRectangle.HorizontalAlignment = HorizontalAlignment.Stretch;

            // Create the object to contain the reflection.
            Rectangle reflectionRectangle = new Rectangle();

            // Bind the height of the rectangle to the border height.
            Binding heightBinding = new Binding();
            heightBinding.ElementName = "ReflectedVisual";
            heightBinding.Path = new PropertyPath(Rectangle.HeightProperty);
            BindingOperations.SetBinding(reflectionRectangle, Rectangle.HeightProperty, heightBinding);

            // Bind the width of the rectangle to the border width.
            Binding widthBinding = new Binding();
            widthBinding.ElementName = "ReflectedVisual";
            widthBinding.Path = new PropertyPath(Rectangle.WidthProperty);
            BindingOperations.SetBinding(reflectionRectangle, Rectangle.WidthProperty, widthBinding);

            // Creates the reflection.
            VisualBrush myVisualBrush = new VisualBrush();
            myVisualBrush.Opacity = 0.75;
            myVisualBrush.Stretch = Stretch.None;
            Binding reflectionBinding = new Binding();
            reflectionBinding.ElementName = "ReflectedVisual";
            BindingOperations.SetBinding(myVisualBrush, VisualBrush.VisualProperty, reflectionBinding);

            ScaleTransform myScaleTransform = new ScaleTransform();
            myScaleTransform.ScaleX = 1;
            myScaleTransform.ScaleY = -1;
            TranslateTransform myTranslateTransform = new TranslateTransform();
            myTranslateTransform.Y = 1;

            TransformGroup myTransformGroup = new TransformGroup();
            myTransformGroup.Children.Add(myScaleTransform);
            myTransformGroup.Children.Add(myTranslateTransform);

            myVisualBrush.RelativeTransform = myTransformGroup;

            reflectionRectangle.Fill = myVisualBrush;

            // Create a gradient background for the border.
            GradientStop firstStop2 = new GradientStop();
            firstStop2.Offset = 0.0;
            Color c1 = new Color();
            c1.R = 0;
            c1.G = 0;
            c1.B = 0;
            c1.A = 255;
            firstStop2.Color = c1;
            GradientStop secondStop2 = new GradientStop();
            secondStop2.Offset = 0.5;
            Color c2 = new Color();
            c2.R = 0;
            c2.G = 0;
            c2.B = 0;
            c2.A = 51;
            firstStop2.Color = c2;
            GradientStop thirdStop = new GradientStop();
            thirdStop.Offset = 0.75;
            Color c3 = new Color();
            c3.R = 0;
            c3.G = 0;
            c3.B = 0;
            c3.A = 0;
            thirdStop.Color = c3;

            GradientStopCollection myGradientStopCollection2 = new GradientStopCollection();
            myGradientStopCollection2.Add(firstStop2);
            myGradientStopCollection2.Add(secondStop2);
            myGradientStopCollection2.Add(thirdStop);

            LinearGradientBrush myLinearGradientBrush2 = new LinearGradientBrush();
            myLinearGradientBrush2.StartPoint = new Point(0.5, 0);
            myLinearGradientBrush2.EndPoint = new Point(0.5, 1);
            myLinearGradientBrush2.GradientStops = myGradientStopCollection2;

            reflectionRectangle.OpacityMask = myLinearGradientBrush2;

            BlurBitmapEffect myBlurBitmapEffect = new BlurBitmapEffect();
            myBlurBitmapEffect.Radius = 1.5;

            reflectionRectangle.BitmapEffect = myBlurBitmapEffect;

            myStackPanel.Children.Add(myReflectedBorder);
            myStackPanel.Children.Add(dividerRectangle);
            myStackPanel.Children.Add(reflectionRectangle);
            this.Content = myStackPanel;

        }
        /*
    <Rectangle 
      Height="{Binding Path=ActualHeight, ElementName=ReflectedVisual}" 
      Width="{Binding Path=ActualWidth, ElementName=ReflectedVisual}">

      <Rectangle.OpacityMask>
        <LinearGradientBrush StartPoint="0.5,0" EndPoint="0.5,1">
          <GradientStop Color="#FF000000" Offset="0.0" />
          <GradientStop Color="#33000000" Offset="0.5" />
          <GradientStop Color="#00000000" Offset="0.75" />
        </LinearGradientBrush>
      </Rectangle.OpacityMask>

      <Rectangle.BitmapEffect>
        <BlurBitmapEffect Radius="1.5" />
      </Rectangle.BitmapEffect>

    </Rectangle>
  </StackPanel>
</Page>

*/

    }
}
<Page  
  xmlns="https://schemas.microsoft.com/winfx/2006/xaml/presentation" 
  xmlns:x="https://schemas.microsoft.com/winfx/2006/xaml" 
  Background="Black">


  <StackPanel Margin="50">

    <!-- The object to reflect. -->
    <Border Name="ReflectedVisual" Width="400">
      <Border.Background>
        <LinearGradientBrush StartPoint="0,0.5" EndPoint="1,0.5">
          <GradientStop Offset="0.0" Color="#CCCCFF" />
          <GradientStop Offset="1.0" Color="White" />
        </LinearGradientBrush>
      </Border.Background>
      <StackPanel Orientation="Horizontal" Margin="10">        
        <TextBlock TextWrapping="Wrap" Width="200" Margin="10">
          Lorem ipsum dolor sit amet, consectetuer adipiscing elit.
          Suspendisse vel ante. Donec luctus tortor sit amet est.
          Nullam pulvinar odio et wisi.
          Pellentesque quis magna. Sed pellentesque.
          Nulla euismod.
          Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas.
        </TextBlock>
        <StackPanel>
          <Ellipse Margin="10" Height="50" Width="50" Fill="Black" />
          <Ellipse Margin="10" Height="50" Width="50" Fill="Black" />
          <Ellipse Margin="10" Height="50" Width="50" Fill="Black" />
        </StackPanel>
      </StackPanel>
    </Border>

    <Rectangle Height="1" Fill="Gray" HorizontalAlignment="Stretch" />

    <!-- The object to contain the reflection.-->
    <Rectangle 
      Height="{Binding Path=ActualHeight, ElementName=ReflectedVisual}" 
      Width="{Binding Path=ActualWidth, ElementName=ReflectedVisual}">
      <Rectangle.Fill>

        <!-- Creates the reflection. -->
        <VisualBrush 
          Opacity="0.75" Stretch="None"
          Visual="{Binding ElementName=ReflectedVisual}">
          <VisualBrush.RelativeTransform>

            <!-- Flip the reflection. -->
            <TransformGroup>
              <ScaleTransform ScaleX="1" ScaleY="-1" />
              <TranslateTransform  Y="1" />
            </TransformGroup>
          </VisualBrush.RelativeTransform>
        </VisualBrush>
      </Rectangle.Fill>

      <Rectangle.OpacityMask>
        <LinearGradientBrush StartPoint="0.5,0" EndPoint="0.5,1">
          <GradientStop Color="#FF000000" Offset="0.0" />
          <GradientStop Color="#33000000" Offset="0.5" />
          <GradientStop Color="#00000000" Offset="0.75" />
        </LinearGradientBrush>
      </Rectangle.OpacityMask>

      <Rectangle.BitmapEffect>
        <BlurBitmapEffect Radius="1.5" />
      </Rectangle.BitmapEffect>

    </Rectangle>
  </StackPanel>
</Page>

Para obtener el ejemplo completo, que incluye ejemplos que muestran cómo aumentar partes de la pantalla y crear reflexiones, vea VisualBrush Sample.

Vea también

Referencia

VisualBrush

Conceptos

Pintar con imágenes, dibujos y elementos visuales