Dynamic Clipping : Clip « Windows Presentation Foundation « VB.Net Tutorial

1. VB.Net Tutorial
2. Windows Presentation Foundation
3. Clip

<StackPanel xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
  xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
  xmlns:d="http://schemas.microsoft.com/expression/interactivedesigner/2006"
  mc:Ignorable="d"
  x:Class="PaintDrawExamples.DynamicClipping" 
  Width="640" Height="480">

    <StackPanel.Resources>
        <Storyboard x:Key="OnLoaded"/>
    </StackPanel.Resources>
    <StackPanel.Triggers>
        <EventTrigger RoutedEvent="FrameworkElement.Loaded">
            <BeginStoryboard x:Name="OnLoaded_BeginStoryboard" Storyboard="{DynamicResource OnLoaded}"/>
        </EventTrigger>
    </StackPanel.Triggers>
    <Canvas Height="100" x:Name="Canvas" Width="436">
        <Canvas.Clip>
            <PathGeometry>
                <PathFigure StartPoint="1,5" IsClosed="True" IsFilled="True">
                    <BezierSegment IsSmoothJoin="True" Point1="2,2" Point2="26,1" Point3="24,127" IsStroked="True"/>
                    <BezierSegment IsSmoothJoin="True" Point1="1,1" Point2="14,9" Point3="19,5" IsStroked="True"/>
                    <BezierSegment IsSmoothJoin="True" Point1="14,11" Point2="18,-22.5" Point3="24,-2" IsStroked="True"/>
                    <BezierSegment IsSmoothJoin="True" Point1="26,-200" Point2="29,1" Point3="300,5" IsStroked="True"/>
                </PathFigure>
            </PathGeometry>
        </Canvas.Clip>
        <Rectangle d:LayoutOverrides="Height" Stroke="{x:Null}" Fill="Red" Width="436" Height="100" x:Name="Rectangle" Canvas.Left="0" Canvas.Top="0"/>
        <Label Background="Black" x:Name="Label" Content="This is my clipped space." Canvas.Left="46" Canvas.Top="26" d:IsHidden="True"/>
    </Canvas>
</StackPanel>
//File:Window.xaml.vb

Imports System
Imports System.IO
Imports System.Net
Imports System.Windows
Imports System.Windows.Input
Imports System.Windows.Controls
Imports System.Windows.Data
Imports System.Windows.Media
Imports System.Windows.Media.Animation
Imports System.Windows.Navigation

Namespace PaintDrawExamples
  Public Partial Class DynamicClipping
    Public Sub New()
      Me.InitializeComponent()
      Me.Canvas.VerticalAlignment = VerticalAlignment.Center
      Me.Canvas.HorizontalAlignment = HorizontalAlignment.Center

      AddHandler CompositionTarget.Rendering, AddressOf CompositionTarget_Rendering
    End Sub

    Private Sub CompositionTarget_Rendering(sender As Object, e As EventArgs)
      Dim mousePos As Point = Mouse.GetPosition(Me.Canvas)
      Dim clippingRegion As Geometry = Me.Canvas.Clip

      Dim newPos As New TranslateTransform()
      newPos.X = mousePos.X - (Me.Canvas.Width / 2)
      newPos.Y = mousePos.Y - (Me.Canvas.Height / 2)

      clippingRegion.Transform = newPos
    End Sub
  End Class
End Namespace

16.85.Clip
	16.85.1.	Dynamic Clipping