我在问题中的 XAML 直接取自关于 SO的这个问题。只是 XAML 创建了一个平铺的 DrawingBrush 以在画布的背景上呈现矩形(在我的例子中为正方形)。我的问题是,这个 XAML 仅在我将画布的宽度和高度设置为“自动”以外的任何值时才有效。但是当我将 canvasMain 的 Width 和 Height 设置为 Auto 时,背景上不会绘制任何正方形。
如何将我的宽度和高度设置为“自动”并让 DrawingBrush 在我的画布上渲染正方形?
这是我的 XAML:
<Window.Resources>
<DrawingBrush x:Key="GridTile" Stretch="None" TileMode="Tile"
Viewport="0,0 20,20" ViewportUnits="Absolute">
<!-- ^^^^^^^^^^^ set the size of the tile-->
<DrawingBrush.Drawing>
<GeometryDrawing>
<GeometryDrawing.Geometry>
<!-- draw a single X -->
<GeometryGroup>
<!-- top-left to top-right -->
<LineGeometry StartPoint="0,0" EndPoint="20,0" />
<!-- top-left to bottom-left -->
<LineGeometry StartPoint="0,0" EndPoint="0,20" />
<!-- bottom-left to bottom-right -->
<LineGeometry StartPoint="0,20" EndPoint="20,20" />
<!-- top-right to bottom-right -->
<LineGeometry StartPoint="20,0" EndPoint="20,20" />
</GeometryGroup>
</GeometryDrawing.Geometry>
<GeometryDrawing.Pen>
<!-- set color and thickness of lines -->
<Pen Thickness="1" Brush="Silver" />
</GeometryDrawing.Pen>
</GeometryDrawing>
</DrawingBrush.Drawing>
</DrawingBrush>
<DrawingBrush x:Key="OffsetGrid" Stretch="None" AlignmentX="Left" AlignmentY="Top">
<DrawingBrush.Transform>
<!-- set the left and top offsets -->
<TranslateTransform X="0" Y="0" />
</DrawingBrush.Transform>
<DrawingBrush.Drawing>
<GeometryDrawing Brush="{StaticResource GridTile}" >
<GeometryDrawing.Geometry>
<!-- set the width and height filled with the tile from the origin -->
<RectangleGeometry Rect="0,0 160,160" />
</GeometryDrawing.Geometry>
</GeometryDrawing>
</DrawingBrush.Drawing>
</DrawingBrush>
</Window.Resources>
<Canvas Name="canvasMain" HorizontalAlignment="Left" Margin="0,0,0,0" VerticalAlignment="Top" Width="Auto" Height="Auto" Background="{StaticResource OffsetGrid}"></Canvas>