PolyBezierSegment Klass

Definition

public ref class PolyBezierSegment sealed : System::Windows::Media::PathSegment

public sealed class PolyBezierSegment : System.Windows.Media.PathSegment

type PolyBezierSegment = class
    inherit PathSegment

Public NotInheritable Class PolyBezierSegment
Inherits PathSegment

Arv

Object

DispatcherObject

DependencyObject

Freezable

Animatable

PathSegment

PolyBezierSegment

Exempel

I följande exempel visas hur du använder en PolyBezierSegment för att rita två kubiska Bezier-kurvor.

<Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
  <StackPanel>
    <Canvas>
      <Path Stroke="Black" StrokeThickness="1">
        <Path.Data>
          <PathGeometry>
            <PathGeometry.Figures>
              <PathFigureCollection>

                <!-- The StartPoint specifies the starting point of the first curve. -->
                <PathFigure StartPoint="10,100">
                  <PathFigure.Segments>
                    <PathSegmentCollection>

                      <!-- The PolyBezierSegment specifies two cubic Bezier curves.
                           The first curve is from 10,100 (start point specified above)
                           to 300,100 with a control point of 0,0 and another control
                           point of 200,0. The second curve is from 300,100 
                           (end of the last curve) to 600,100 with a control point of 300,0
                           and another control point of 400,0. -->
                      <PolyBezierSegment Points="0,0 200,0 300,100 300,0 400,0 600,100" />
                    </PathSegmentCollection>
                  </PathFigure.Segments>
                </PathFigure>
              </PathFigureCollection>
            </PathGeometry.Figures>
          </PathGeometry>
        </Path.Data>
      </Path>
    </Canvas>
  </StackPanel>
</Page>

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Shapes;

namespace SDKSample
{
    public partial class PolyBezierSegmentExample : Page
    {
        public PolyBezierSegmentExample()
        {

            // Create a PathFigure to be used for the PathGeometry of myPath.
            PathFigure myPathFigure = new PathFigure();

            // Set the starting point for the PathFigure specifying that the
            // geometry starts at point 10,100.
            myPathFigure.StartPoint = new Point(10, 100);

            // Create a PointCollection that holds the Points used to specify 
            // the points of the PolyBezierSegment below.
            PointCollection myPointCollection = new PointCollection(6);
            myPointCollection.Add(new Point(0, 0));
            myPointCollection.Add(new Point(200, 0));
            myPointCollection.Add(new Point(300, 100));
            myPointCollection.Add(new Point(300, 0));
            myPointCollection.Add(new Point(400, 0));
            myPointCollection.Add(new Point(600, 100));

            // The PolyBezierSegment specifies two cubic Bezier curves.
            // The first curve is from 10,100 (start point specified by the PathFigure)
            // to 300,100 with a control point of 0,0 and another control point 
            // of 200,0. The second curve is from 300,100 (end of the last curve) to 
            // 600,100 with a control point of 300,0 and another control point of 400,0.
            PolyBezierSegment myBezierSegment = new PolyBezierSegment();
            myBezierSegment.Points = myPointCollection;

            PathSegmentCollection myPathSegmentCollection = new PathSegmentCollection();
            myPathSegmentCollection.Add(myBezierSegment);

            myPathFigure.Segments = myPathSegmentCollection;

            PathFigureCollection myPathFigureCollection = new PathFigureCollection();
            myPathFigureCollection.Add(myPathFigure);

            PathGeometry myPathGeometry = new PathGeometry();
            myPathGeometry.Figures = myPathFigureCollection;

            // Create a path to draw a geometry with.
            Path myPath = new Path();
            myPath.Stroke = Brushes.Black;
            myPath.StrokeThickness = 1;

            // specify the shape (quadratic Bezier curve) of the path using the StreamGeometry.
            myPath.Data = myPathGeometry;

            // Add path shape to the UI.
            StackPanel mainPanel = new StackPanel();
            mainPanel.Children.Add(myPath);
            this.Content = mainPanel;
        }
    }
}

Imports System.Windows
Imports System.Windows.Controls
Imports System.Windows.Media
Imports System.Windows.Shapes

Namespace SDKSample
    Partial Public Class PolyBezierSegmentExample
        Inherits Page
        Public Sub New()

            ' Create a PathFigure to be used for the PathGeometry of myPath.
            Dim myPathFigure As New PathFigure()

            ' Set the starting point for the PathFigure specifying that the
            ' geometry starts at point 10,100.
            myPathFigure.StartPoint = New Point(10, 100)

            ' Create a PointCollection that holds the Points used to specify 
            ' the points of the PolyBezierSegment below.
            Dim myPointCollection As New PointCollection(6)
            myPointCollection.Add(New Point(0, 0))
            myPointCollection.Add(New Point(200, 0))
            myPointCollection.Add(New Point(300, 100))
            myPointCollection.Add(New Point(300, 0))
            myPointCollection.Add(New Point(400, 0))
            myPointCollection.Add(New Point(600, 100))

            ' The PolyBezierSegment specifies two cubic Bezier curves.
            ' The first curve is from 10,100 (start point specified by the PathFigure)
            ' to 300,100 with a control point of 0,0 and another control point 
            ' of 200,0. The second curve is from 300,100 (end of the last curve) to 
            ' 600,100 with a control point of 300,0 and another control point of 400,0.
            Dim myBezierSegment As New PolyBezierSegment()
            myBezierSegment.Points = myPointCollection

            Dim myPathSegmentCollection As New PathSegmentCollection()
            myPathSegmentCollection.Add(myBezierSegment)

            myPathFigure.Segments = myPathSegmentCollection

            Dim myPathFigureCollection As New PathFigureCollection()
            myPathFigureCollection.Add(myPathFigure)

            Dim myPathGeometry As New PathGeometry()
            myPathGeometry.Figures = myPathFigureCollection

            ' Create a path to draw a geometry with.
            Dim myPath As New Path()
            myPath.Stroke = Brushes.Black
            myPath.StrokeThickness = 1

            ' specify the shape (quadratic Bezier curve) of the path using the StreamGeometry.
            myPath.Data = myPathGeometry

            ' Add path shape to the UI.
            Dim mainPanel As New StackPanel()
            mainPanel.Children.Add(myPath)
            Me.Content = mainPanel
        End Sub
    End Class
End Namespace

Kommentarer

Använd ett PathFigure objekt för att lagra PolyBezierSegment objekt och andra segment.

En kubisk Bezier-kurva definieras av fyra punkter: en startpunkt, en slutpunkt och två kontrollpunkter. A PolyBezierSegment anger en eller flera kubiska Bezier-kurvor genom att ställa in Points egenskapen på en samling punkter. För var tredje punkt i samlingen anger den första och andra punkten de två kontrollpunkterna i kurvan och den tredje punkten anger slutpunkten. Observera att ingen startpunkt för kurvan har angetts eftersom startpunkten är samma som slutpunkten för det sista segmentet.

De två kontrollpunkterna i en kubisk Bezier-kurva beter sig som magneter, lockar delar av vad som annars skulle vara en rak linje mot sig själva och producerar en kurva. Den första kontrollpunkten påverkar början av kurvan. den andra kontrollpunkten påverkar slutdelen av kurvan. Observera att kurvan inte nödvändigtvis passerar någon av kontrollpunkterna. varje kontrollpunkt flyttar sin del av linjen mot sig själv, men inte genom sig själv.

Se även

• BezierSegment