Wpf – DynamicResource color doesn’t work for BorderBrush on a Border – Bug

borderc#-4.0dynamicresourcewpf

Visual Studio 2010 | .NET/WPF 4.0

I think this might be a WPF bug, but I can't seem to find a bug report about it. To cover the possibility that I'm just missing something obvious, I turn to stackoverflow for answers!

Consider this xaml (nothing in the codebehind):

<Window x:Class="DownExpanders.BorderTest"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="BorderTest" Height="300" Width="300">
    <Window.Resources>
        <Color x:Key="BackgroundColor" R="255" G="0" B="0" A="255"/>
        <Color x:Key="BorderColor" R="0" G="0" B="255" A="255"/>
        <SolidColorBrush x:Key="BorderColorBrush" Color="{DynamicResource BorderColor}"/>
    </Window.Resources>
    <Grid>
        <Border BorderThickness="20">
            <Border.Background>
                <SolidColorBrush Color="{DynamicResource BackgroundColor}"/>
            </Border.Background>
            <Border.BorderBrush>
                <SolidColorBrush Color="{DynamicResource BorderColor}"/>
            </Border.BorderBrush>
        </Border>

        <Border Margin="40" BorderBrush="{DynamicResource BorderColorBrush}" BorderThickness="20"/>
    </Grid>
</Window>

In the designer, it renders as expected. The outer border has a big blue border and a red background, the inner border has a big blue border. Great.

When I run the code, the outer border has NO border – it looks like it just doesn't load. The background is set to red correctly. Meanwhile, the inner border does load its blue border correctly.

If I change all "DynamicResource" to "StaticResource", it renders correctly when run. The inconsistency is really bugging me, and I can't figure it out.\

So:

  1. Why doesn't DynamicResource work for BorderBrush?
  2. Given #1, why does it work for Background?
  3. Why does explicitly defining the solid color brush in the resources seem to fix things?

EDIT:

Looks like it's a bug that MS decided not to fix (thanks to Sheridan for the link): http://connect.microsoft.com/VisualStudio/feedback/details/589898/wpf-border-borderbrush-does-not-see-changes-in-dynamic-resource

Best Answer

This doesn't seem to be the case with the RadialGradientBrush.

<Window x:Class="WpfApplication3.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">

    <Grid>
        <Grid.Resources>
            <Color x:Key="BackgroundColor" R="255" G="0" B="0" A="255"/>
            <Color x:Key="BorderColor" R="0" G="0" B="255" A="255"/>
            <SolidColorBrush x:Key="BorderColorBrush" Color="{DynamicResource BorderColor}"/>
        </Grid.Resources>
        <Border BorderThickness="20">
            <Border.BorderBrush>
                <RadialGradientBrush>
                    <GradientStop Color="{DynamicResource BorderColor}"/>
                    <GradientStop Color="{DynamicResource BorderColor}"/>
                </RadialGradientBrush>
            </Border.BorderBrush>
            <Border.Background>
                <SolidColorBrush Color="{DynamicResource BackgroundColor}"/>
            </Border.Background>
        </Border>

        <Border Margin="40" BorderBrush="{DynamicResource BorderColorBrush}" BorderThickness="20"/>

    </Grid>
</Window>

enter image description here

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