C# 通过代码隐藏创建VisualBrush

我将此示例作为XAML：

<VisualBrush x:Key="HatchBrush" TileMode="Tile" Viewport="0,0,5,5" ViewportUnits="Absolute" Viewbox="0,0,5,5" ViewboxUnits="Absolute" po:Freeze="True">
<VisualBrush.Visual>
<Path Data="M 0 5 L 5 0 M -2 2 L 2 -2 M 3 7 L 7 3"
    Stroke="#80ffffff" StrokeEndLineCap="Square"
    RenderOptions.EdgeMode="Aliased" />
</VisualBrush.Visual>

老实说，我不知道如何写路径数据。我该怎么做呢？

你可以写

vb.Visual = new Path
{
    Data = Geometry.Parse("M 0 5 L 5 0 M -2 2 L 2 -2 M 3 7 L 7 3"),
    Stroke = new SolidColorBrush(Color.FromArgb(0x80, 0xff, 0xff, 0xff))
};

但是，您根本不需要使用VisualBrush

下面的XAML演示了如何使用带有两个图形的DrawingBrush在纯色背景上获得填充图案

<DrawingBrush x:Key="HatchBrush" TileMode="Tile"
              Viewport="0,0,5,5" ViewportUnits="Absolute"
              Viewbox="0,0,5,5" ViewboxUnits="Absolute">
    <DrawingBrush.Drawing>
        <DrawingGroup>
            <GeometryDrawing Brush="DarkCyan">
                <GeometryDrawing.Geometry>
                    <RectangleGeometry Rect="0,0,5,5"/>
                </GeometryDrawing.Geometry>
            </GeometryDrawing>
            <GeometryDrawing Geometry="M0,5 L5,0 M-2,2 L2,-2 M3,7 L7,3">
                <GeometryDrawing.Pen>
                    <Pen Brush="#80ffffff" Thickness="1"/>
                </GeometryDrawing.Pen>
            </GeometryDrawing>
        </DrawingGroup>
    </DrawingBrush.Drawing>
</DrawingBrush>

---

路径是常数还是取决于某些参数？if constant：将其定义为一个资源，并在代码中选择该资源以指定VisualPath为常量，但我必须在代码隐藏中执行的原因是，我需要将现有笔刷与solidcolor组合；我会在solidcolor填充上绘制弯曲的线条。这不是在代码中这样做的理由。DrawingBrush允许在DrawingGroup中使用多个不同的图形。

<DrawingBrush x:Key="HatchBrush" TileMode="Tile"
              Viewport="0,0,5,5" ViewportUnits="Absolute"
              Viewbox="0,0,5,5" ViewboxUnits="Absolute">
    <DrawingBrush.Drawing>
        <DrawingGroup>
            <GeometryDrawing Brush="DarkCyan">
                <GeometryDrawing.Geometry>
                    <RectangleGeometry Rect="0,0,5,5"/>
                </GeometryDrawing.Geometry>
            </GeometryDrawing>
            <GeometryDrawing Geometry="M0,5 L5,0 M-2,2 L2,-2 M3,7 L7,3">
                <GeometryDrawing.Pen>
                    <Pen Brush="#80ffffff" Thickness="1"/>
                </GeometryDrawing.Pen>
            </GeometryDrawing>
        </DrawingGroup>
    </DrawingBrush.Drawing>
</DrawingBrush>