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Friday, March 7, 2008

WPF TileBrush Nonsense

For the absolute life of me I cannot get a custom TileBrush to tile outside of VS2k8 or Blend 2.5. The basics are that I'm constructing a ruler, which started programmatically after finding the current DPI. When that didn't work, I attempted to do the same thing in straight XAML, which wouldn't be relative to the DPI (thus would only be a nice ruler at 96dpi). Even this would not work. At this point my frustration knows no bounds.

The above is a screengrab from inside VS2k8. The screengrab from Blend 2.5 also shows the ruler tiling. Below is a screengrab during runtime, notice the distinctive lack of tiling, and now it is somehow stretching to Fill.

The tiled brush is a DrawingBrush consisting of a GeometryDrawing with a GeometryGroup of LineGeometry's. The annotated XAML is given below:
<DrawingBrush x:Key="RulerBrush"
Stretch="None"
TileMode="Tile"
Viewport="0,0,96,16"
ViewportUnits="Absolute"
Viewbox="0 0 1 1"
ViewboxUnits="RelativeToBoundingBox">
<DrawingBrush.Drawing>
<GeometryDrawing>
<GeometryDrawing.Geometry>
<GeometryGroup>
<LineGeometry EndPoint="0,16"
StartPoint="0,0" />
<!-- ... -->
<LineGeometry EndPoint="48,16"
StartPoint="48,4" />
<!-- ... -->
<LineGeometry EndPoint="96,16"
StartPoint="96,0" />
</GeometryGroup>
</GeometryDrawing.Geometry>
<GeometryDrawing.Pen>
<Pen Brush="#FF000000"
Thickness="1" />
</GeometryDrawing.Pen>
</GeometryDrawing>
</DrawingBrush.Drawing>
</DrawingBrush>

And the requisite XAML for the display area:
<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
x:Class="Test.Window1"
x:Name="Window"
Title="Window"
Width="640"
Height="480">
<DockPanel x:Name="LayoutRoot" LastChildFill="True">
<ToolBarTray x:Name="ToolBarTray"
DockPanel.Dock="Top">
<ToolBar x:Name="MenuToolBar"
ToolBar.Band="0"
Width="{Binding Path=ActualWidth, ElementName=ToolBarTray}" />
</ToolBarTray>
<Rectangle x:Name="RulerY"
DockPanel.Dock="Left"
Height="15" Margin="0,15,0,0"
Fill="{DynamicResource RulerBrush}">
<Rectangle.LayoutTransform>
<RotateTransform Angle="-90.0" />
</Rectangle.LayoutTransform>
</Rectangle>
<Rectangle x:Name="RulerX"
DockPanel.Dock="Top"
Height="15" Margin="0,0,0,0"
Fill="{DynamicResource RulerBrush}"/>
<ScrollViewer Style="{DynamicResource SimpleScrollViewer}"/>
</DockPanel>
</Window>

This is fairly obnoxious!