I'm trying to make a control that draws a red cross in its center. I want the cross to be one pixel wide, and I want to disable antialiasing and make it snap to the screen's pixels.
The control works, but if I add it inside a Grid that has a splitter, when I drag the splitter one of the lines will sometimes disappear. If I put it inside a grid with a horizontal splitter, the horizontal line will sometimes disappear and if I put it inside a grid with a vertical splitter, the vertical line will sometimes disappear.
How can I stop the lines from disappearing?
Here is the xaml code:
<Window x:Class="WpfTest.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:WpfTest"
Title="MainWindow" Height="600" Width="800">
<Window.Resources>
<local:HalfValueConverter x:Key="halfConv" />
<Style TargetType="Line">
<Setter Property="Stroke" Value="Red"/>
<Setter Property="StrokeThickness" Value="1"/>
<Setter Property="RenderOptions.EdgeMode" Value="Aliased"/>
<Setter Property="SnapsToDevicePixels" Value="True" />
</Style>
</Window.Resources>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="*"/>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<Grid Grid.Row="2" Background="Black" Name="grdParent">
<Line X1="{Binding ActualWidth, ElementName=grdParent, Converter={StaticResource halfConv}}"
Y1="0"
X2="{Binding ActualWidth, ElementName=grdParent, Converter={StaticResource halfConv}}"
Y2="{Binding ActualHeight, RelativeSource={x:Static RelativeSource.Self}}"
Height="100"
/>
<Line X1="0"
Y1="{Binding ActualHeight, ElementName=grdParent, Converter={StaticResource halfConv}}"
X2="{Binding ActualWidth, RelativeSource={x:Static RelativeSource.Self}}"
Y2="{Binding ActualHeight, ElementName=grdParent, Converter={StaticResource halfConv}}"
Width="100"
/>
</Grid>
<GridSplitter Grid.Row="1" Height="5" HorizontalAlignment="Stretch" Background="Gray" ResizeBehavior="PreviousAndNext" ResizeDirection="Rows" />
</Grid>
</Window>
And here is the code for the HalfValueConverter:
using System;
using System.Windows.Data;
namespace WpfTest
{
public class HalfValueConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
return ((double)value / 2);
}
public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
return ((double)value * 2);
}
}
}
This is how it looks when you drag the splitter into the right position:
And this is how it should look:
