StreamGeometryContext.LineTo(Point, Boolean, Boolean) 方法

定义

命名空间:

System.Windows.Media

程序集:

PresentationCore.dll

绘制一条到指定的 Point 的直线。

public:
 abstract void LineTo(System::Windows::Point point, bool isStroked, bool isSmoothJoin);

public abstract void LineTo (System.Windows.Point point, bool isStroked, bool isSmoothJoin);

abstract member LineTo : System.Windows.Point * bool * bool -> unit

Public MustOverride Sub LineTo (point As Point, isStroked As Boolean, isSmoothJoin As Boolean)

参数

point

Point

直线末尾的目标点。

isStroked

Boolean

若要在使用 Pen 呈现线段时使线段描边，则为 true；否则为 false。

isSmoothJoin

Boolean

在用 Pen 描边时，如果要将此线段与前一条线段之间的联接视为角，则为 true；否则为 false。

例外

InvalidOperationException

试图添加一条线段，但未通过调用 BeginFigure(Point, Boolean, Boolean) 方法来指定图形的起点。

示例

以下示例演示如何使用 LineTo 方法绘制三角形。

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

namespace SDKSample
{
    // Use StreamGeometry with StreamGeometryContext to define a triangle shape.
    public partial class StreamGeometryTriangleExample : Page
    {
        public StreamGeometryTriangleExample()
        {
            // 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())
            {
                
                // Begin the triangle at the point specified. Notice that the shape is set to 
                // be closed so only two lines need to be specified below to make the triangle.
                ctx.BeginFigure(new Point(10, 100), true /* is filled */, true /* is closed */);

                // Draw a line to the next specified point.
                ctx.LineTo(new Point(100, 100), true /* is stroked */, false /* is smooth join */);

                // Draw another line to the next specified point.
                ctx.LineTo(new Point(100, 50), true /* is stroked */, false /* is smooth join */);
            }

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

            // Specify the shape (triangle) 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
    ' Use StreamGeometry with StreamGeometryContext to define a triangle shape.
    Partial Public Class StreamGeometryTriangleExample
        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()

                ' Begin the triangle at the point specified. Notice that the shape is set to 
                ' be closed so only two lines need to be specified below to make the triangle.
                ctx.BeginFigure(New Point(10, 100), True, True) ' is closed  -  is filled 

                ' Draw a line to the next specified point.
                ctx.LineTo(New Point(100, 100), True, False) ' is smooth join  -  is stroked 

                ' Draw another line to the next specified point.
                ctx.LineTo(New Point(100, 50), True, False) ' is smooth join  -  is stroked 
            End Using

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

            ' Specify the shape (triangle) 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

注解

此方法使用上一段的终结点作为起点。 如果这是图中的第一段，则使用 方法指定的 BeginFigure 点作为起点。

StreamGeometry如果 包含 Transform 或任何非笔划或未填充段，则无法序列化 。

另请参阅

• PolyLineTo(IList<Point>, Boolean, Boolean)