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StreamGeometryContext.PolyQuadraticBezierTo Method

  • Reference

Definition

Namespace:
System.Windows.Media
Assembly:
PresentationCore.dll

Draws one or more connected quadratic Bezier curves.

public:
 abstract void PolyQuadraticBezierTo(System::Collections::Generic::IList<System::Windows::Point> ^ points, bool isStroked, bool isSmoothJoin);
public abstract void PolyQuadraticBezierTo (System.Collections.Generic.IList<System.Windows.Point> points, bool isStroked, bool isSmoothJoin);
abstract member PolyQuadraticBezierTo : System.Collections.Generic.IList<System.Windows.Point> * bool * bool -> unit
Public MustOverride Sub PolyQuadraticBezierTo (points As IList(Of Point), isStroked As Boolean, isSmoothJoin As Boolean)

Parameters

points
IList<Point>

The collection of points that specify control points and destination points for one or more quadratic Bezier curves. The first point in the list specifies the curve's control point, the next point specifies the destination point, the next point specifies the control point of the next curve, and so on. The list must contain an even number of points.

isStroked
Boolean

true to make the segment stroked when a Pen is used to render the segment; otherwise, false.

isSmoothJoin
Boolean

true to treat the join between this segment and the previous segment as a corner when stroked with a Pen; otherwise, false.

Exceptions

InvalidOperationException

An attempt was made to add a segment without starting a figure by calling the BeginFigure(Point, Boolean, Boolean) method.

Examples

The following example shows how to draw multiple connected quadratic Bezier curves using the PolyQuadraticBezierTo method.

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

namespace SDKSample
{
    public partial class StreamGeometryPolyQuadraticBezierToExample : Page
    {
        public StreamGeometryPolyQuadraticBezierToExample()
        {
            // Create a path to draw a geometry with.
            Path myPath = new Path();
            myPath.Stroke = Brushes.Black;
            myPath.StrokeThickness = 1;

            // Create a StreamGeometry to use to specify myPath.
            StreamGeometry geometry = new StreamGeometry();
            geometry.FillRule = FillRule.EvenOdd;

            // Open a StreamGeometryContext that can be used to describe this StreamGeometry object's contents. 
            using (StreamGeometryContext ctx = geometry.Open())
            {
                // Set the begin point of the shape.
                ctx.BeginFigure(new Point(10, 100), true /* is filled */, false /* is closed */);

                // Create a collection of Point structures that will be used with the PolyQuadraticBezierTo 
                // Method to create two quadratic Bezier curves.
                List<Point> pointList = new List<Point>();

                // First quadratic Bezier curve is specified with these two points.

                // Control point for first quadratic Bezier curve.
                pointList.Add(new Point(100, 0));

                // End point for first quadratic Bezier curve.
                pointList.Add(new Point(200, 200));

                // Second quadratic Bezier curve is specified with these two points.

                // Control point for second quadratic Bezier curve.
                pointList.Add(new Point(300, 300));

                // End point for second quadratic Bezier curve.
                pointList.Add(new Point(400, 100));

                // Create a Bezier curve using the collection of Point Structures.
                ctx.PolyQuadraticBezierTo(pointList, true /* is stroked */, false /* is smooth join */);
            }

            // Freeze the geometry (make it unmodifiable)
            // for additional performance benefits.
            geometry.Freeze();
            
            // specify the shape (quadratic Benzier curve) of the path using the StreamGeometry.
            myPath.Data = geometry;

            // 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
Imports System.Collections.Generic

Namespace SDKSample
    Partial Public Class StreamGeometryPolyQuadraticBezierToExample
        Inherits Page
        Public Sub New()
            ' Create a path to draw a geometry with.
            Dim myPath As New Path()
            myPath.Stroke = Brushes.Black
            myPath.StrokeThickness = 1

            ' Create a StreamGeometry to use to specify myPath.
            Dim geometry As New StreamGeometry()
            geometry.FillRule = FillRule.EvenOdd

            ' Open a StreamGeometryContext that can be used to describe this StreamGeometry object's contents. 
            Using ctx As StreamGeometryContext = geometry.Open()
                ' Set the begin point of the shape.
                ctx.BeginFigure(New Point(10, 100), True, False) ' is closed  -  is filled 

                ' Create a collection of Point structures that will be used with the PolyQuadraticBezierTo 
                ' Method to create two quadratic Bezier curves.
                Dim pointList As New List(Of Point)()

                ' First quadratic Bezier curve is specified with these two points.

                ' Control point for first quadratic Bezier curve.
                pointList.Add(New Point(100, 0))

                ' End point for first quadratic Bezier curve.
                pointList.Add(New Point(200, 200))

                ' Second quadratic Bezier curve is specified with these two points.

                ' Control point for second quadratic Bezier curve.
                pointList.Add(New Point(300, 300))

                ' End point for second quadratic Bezier curve.
                pointList.Add(New Point(400, 100))

                ' Create a Bezier curve using the collection of Point Structures.
                ctx.PolyQuadraticBezierTo(pointList, True, False) ' is smooth join  -  is stroked 

            End Using

            ' Freeze the geometry (make it unmodifiable)
            ' for additional performance benefits.
            geometry.Freeze()

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

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

Remarks

This method uses the end point of the previous segment as its starting point. If this is the first segment in a figure, it uses the point specified by the BeginFigure method as its start point.

A StreamGeometry cannot be serialized if it contains a Transform or any non-stroked or unfilled segments.

Applies to

See also