Procedura: definire una penna

In questo esempio viene illustrato come utilizzare un Pen oggetto per delineare una forma. Per creare un semplice Pen, è necessario specificare solo il relativo Thickness e Brush. È possibile creare una penna più complessa specificando un DashStyleoggetto , DashCap, LineJoinStartLineCap, e EndLineCap.

Esempio

Nell'esempio seguente viene utilizzato un Pen oggetto per delineare una forma definita da un oggetto GeometryDrawing.

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
namespace SDKSample
{
    public partial class PenExample : Page
    {
        public PenExample()
        {
            // Create several geometries.
            RectangleGeometry myRectangleGeometry = new RectangleGeometry();
            myRectangleGeometry.Rect = new Rect(0, 0, 50, 50);
            EllipseGeometry myEllipseGeometry = new EllipseGeometry();
            myEllipseGeometry.Center = new Point(75, 75);
            myEllipseGeometry.RadiusX = 50;
            myEllipseGeometry.RadiusY = 50;
            LineGeometry myLineGeometry = new LineGeometry();
            myLineGeometry.StartPoint = new Point(75, 75);
            myLineGeometry.EndPoint = new Point(75, 0);

            // Create a GeometryGroup and add the geometries to it.
            GeometryGroup myGeometryGroup = new GeometryGroup();
            myGeometryGroup.Children.Add(myRectangleGeometry);
            myGeometryGroup.Children.Add(myEllipseGeometry);
            myGeometryGroup.Children.Add(myLineGeometry);

            // Create a GeometryDrawing and use the GeometryGroup to specify
            // its geometry.
            GeometryDrawing myGeometryDrawing = new GeometryDrawing();
            myGeometryDrawing.Geometry = myGeometryGroup;

            // Add the GeometryDrawing to a DrawingGroup.
            DrawingGroup myDrawingGroup = new DrawingGroup();
            myDrawingGroup.Children.Add(myGeometryDrawing);

            // Create a Pen to add to the GeometryDrawing created above.
            Pen myPen = new Pen();
            myPen.Thickness = 10;
            myPen.LineJoin = PenLineJoin.Round;
            myPen.EndLineCap = PenLineCap.Round;

            // Create a gradient to use as a value for the Pen's Brush property.
            GradientStop firstStop = new GradientStop();
            firstStop.Offset = 0.0;
            Color c1 = new Color();
            c1.A = 255;
            c1.R = 204;
            c1.G = 204;
            c1.B = 255;
            firstStop.Color = c1;
            GradientStop secondStop = new GradientStop();
            secondStop.Offset = 1.0;
            secondStop.Color = Colors.Purple;

            LinearGradientBrush myLinearGradientBrush = new LinearGradientBrush();
            myLinearGradientBrush.GradientStops.Add(firstStop);
            myLinearGradientBrush.GradientStops.Add(secondStop);

            myPen.Brush = myLinearGradientBrush;
            myGeometryDrawing.Pen = myPen;

            // Create an Image and set its DrawingImage to the Geometry created above.
            Image myImage = new Image();
            myImage.Stretch = Stretch.None;
            myImage.Margin = new Thickness(10);

            DrawingImage myDrawingImage = new DrawingImage();
            myDrawingImage.Drawing = myDrawingGroup;
            myImage.Source = myDrawingImage;

            this.Content = myImage;
        }
    }
}

Imports System.Windows
Imports System.Windows.Controls
Imports System.Windows.Media
Namespace SDKSample
    Partial Public Class PenExample
        Inherits Page
        Public Sub New()
            ' Create several geometries.
            Dim myRectangleGeometry As New RectangleGeometry()
            myRectangleGeometry.Rect = New Rect(0, 0, 50, 50)
            Dim myEllipseGeometry As New EllipseGeometry()
            myEllipseGeometry.Center = New Point(75, 75)
            myEllipseGeometry.RadiusX = 50
            myEllipseGeometry.RadiusY = 50
            Dim myLineGeometry As New LineGeometry()
            myLineGeometry.StartPoint = New Point(75, 75)
            myLineGeometry.EndPoint = New Point(75, 0)

            ' Create a GeometryGroup and add the geometries to it.
            Dim myGeometryGroup As New GeometryGroup()
            myGeometryGroup.Children.Add(myRectangleGeometry)
            myGeometryGroup.Children.Add(myEllipseGeometry)
            myGeometryGroup.Children.Add(myLineGeometry)

            ' Create a GeometryDrawing and use the GeometryGroup to specify
            ' its geometry.
            Dim myGeometryDrawing As New GeometryDrawing()
            myGeometryDrawing.Geometry = myGeometryGroup

            ' Add the GeometryDrawing to a DrawingGroup.
            Dim myDrawingGroup As New DrawingGroup()
            myDrawingGroup.Children.Add(myGeometryDrawing)

            ' Create a Pen to add to the GeometryDrawing created above.
            Dim myPen As New Pen()
            myPen.Thickness = 10
            myPen.LineJoin = PenLineJoin.Round
            myPen.EndLineCap = PenLineCap.Round

            ' Create a gradient to use as a value for the Pen's Brush property.
            Dim firstStop As New GradientStop()
            firstStop.Offset = 0.0
            Dim c1 As New Color()
            c1.A = 255
            c1.R = 204
            c1.G = 204
            c1.B = 255
            firstStop.Color = c1
            Dim secondStop As New GradientStop()
            secondStop.Offset = 1.0
            secondStop.Color = Colors.Purple

            Dim myLinearGradientBrush As New LinearGradientBrush()
            myLinearGradientBrush.GradientStops.Add(firstStop)
            myLinearGradientBrush.GradientStops.Add(secondStop)

            myPen.Brush = myLinearGradientBrush
            myGeometryDrawing.Pen = myPen

            ' Create an Image and set its DrawingImage to the Geometry created above.
            Dim myImage As New Image()
            myImage.Stretch = Stretch.None
            myImage.Margin = New Thickness(10)

            Dim myDrawingImage As New DrawingImage()
            myDrawingImage.Drawing = myDrawingGroup
            myImage.Source = myDrawingImage

            Me.Content = myImage

        End Sub
    End Class
End Namespace

GeometryDrawing