StreamGeometryContext.QuadraticBezierTo 方法

  • 參考

定義

命名空間:
System.Windows.Media
組件:
PresentationCore.dll

繪製二次方貝茲曲線。

public:
 abstract void QuadraticBezierTo(System::Windows::Point point1, System::Windows::Point point2, bool isStroked, bool isSmoothJoin);
public abstract void QuadraticBezierTo (System.Windows.Point point1, System.Windows.Point point2, bool isStroked, bool isSmoothJoin);
abstract member QuadraticBezierTo : System.Windows.Point * System.Windows.Point * bool * bool -> unit
Public MustOverride Sub QuadraticBezierTo (point1 As Point, point2 As Point, isStroked As Boolean, isSmoothJoin As Boolean)

參數

point1
Point

用來指定曲線圖案的控制點。

point2
Point

曲線結尾的目的點。

isStroked
Boolean

使用 Pen 轉譯區段，將區段劃上底線時，則為 true，否則為 false。

isSmoothJoin
Boolean

使用 Pen 畫底線時，將這個區段和前一個區段之間的這個聯結視為邊角，則為 true，否則為 false。

例外狀況

InvalidOperationException

嘗試加入區段，而不需呼叫 BeginFigure(Point, Boolean, Boolean) 方法來啟動圖表。

範例

下列範例示範如何使用 方法繪製二次方 Bezier 曲線 QuadraticBezierTo 。

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

namespace SDKSample
{
    public partial class StreamGeometryQuadraticBezierToExample : Page
    {
        public StreamGeometryQuadraticBezierToExample()
        {
            // 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();

            // 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 Quadratic Bezier curve using the 2 specifed points. The first point
                // specifies the control point while the second point specifies the end point 
                // of the curve.
                ctx.QuadraticBezierTo(new Point(100, 0), new Point(200, 200), true /* is stroked */, 
                                      false /* is smooth join */);
            }

            // Freeze the geometry (make it unmodifiable)
            // for additional performance benefits.
            geometry.Freeze();
            
            // specify the shape (quadratic Bezier 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

Namespace SDKSample
    Partial Public Class StreamGeometryQuadraticBezierToExample
        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()

            ' 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 Quadratic Bezier curve using the 2 specifed points. The first point
                ' specifies the control point while the second point specifies the end point 
                ' of the curve.
                ctx.QuadraticBezierTo(New Point(100, 0), New Point(200, 200), 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 Bezier 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

備註

不同于使用兩個控制點的三次方 Bezier 曲線，二次方 Bezier 曲線會使用單一控制點。

這個方法會使用上一個區段的終點做為其起點。 如果這是圖中的第一個區段，它會使用 方法所 BeginFigure 指定的點做為其起點。

StreamGeometry如果它包含 Transform 或任何非筆劃或未填滿的區段，則無法序列化 。

適用於

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