WPF GeometryDrawing Pen 无法从代码中工作

问题描述

此代码段有效：

  <Image Canvas.Left="50" Canvas.Top="0" Width="40" Height="30" ClipToBounds="False">
    <Image.source>
      <DrawingImage>
        <DrawingImage.Drawing>
          <GeometryDrawing>
            <GeometryDrawing.Pen>
              <Pen Brush="AliceBlue" Thickness=".05" />
            </GeometryDrawing.Pen>
            <GeometryDrawing.Brush>
              <ImageBrush ImageSource="pack://application:,/MyApp;component/Resources/SomePicture.png" />
            </GeometryDrawing.Brush>
            <GeometryDrawing.Geometry>
              <PathGeometry>
                <Pathfigure StartPoint="0,3" IsClosed="True" IsFilled="True">
                  <PathSegmentCollection>
                    <Linesegment Point="0,0" />
                    <Linesegment Point="3,3" />
                    <Linesegment Point="0,3" />
                  </PathSegmentCollection>
                </Pathfigure>
              </PathGeometry>
            </GeometryDrawing.Geometry>
          </GeometryDrawing>
        </DrawingImage.Drawing>
      </DrawingImage>
    </Image.source>
  </Image>

它显示的图像带有由 Pen 中的 GeometryDrawing 定义的 AliceBlue 边框，无论是在 VS Designer 中还是在编译的应用程序中。

现在我想在代码中做同样的事情，但除了 Pen 之外，一切正常。

Pathfigure pathfigure = new Pathfigure() {
    StartPoint = new Point(0,3),IsClosed = true,IsFilled = true,};
pathfigure.Segments.Add(new Linesegment(new Point(0,0)));
pathfigure.Segments.Add(new Linesegment(new Point(3,3)));
pathfigure.Segments.Add(new Linesegment(new Point(0,3)));
PathGeometry geometryImage = new PathGeometry();
geometryImage.figures.Add(pathfigure);
DrawingImage drawingImage = new DrawingImage(new GeometryDrawing() {
    Pen = new Pen(Brushes.Red,1),// Pen is not applied!
    Brush = new ImageBrush(bitmap),// A prevIoUsly loaded BitmapSource
    Geometry = geometryImage,});
drawingImage.Freeze();
Image image = new() { // In case you wonder,this is valid Now in C#
    ClipToBounds = false,Stretch = Stretch.Fill,Source = drawingImage,};

这复制了与 XAML 示例完全相同的图像，除了 Pen 奇迹般地没有被应用。我在这里错过了什么？

解决方法

正如 Andy 在评论中指出的，Segment 带有一个 IsStroked 构造函数参数，该参数需要设置为 true。在 XAML 中，此值默认为 true。