How to dynamically bind a run's background brush to a resource?

Question

In my app.xaml:

<Application.Resources>
    <SolidColorBrush x:Key="colorBrush1" Color="Orange" Opacity="1"/>
    <SolidColorBrush x:Key="colorBrush2" Color="Green" Opacity="1"/>
</Application.Resources>

In my code-behind:

Run run = new Run("My name is Bob!");
run.SetResourceReference(ForegroundProperty, "colorBrush1");
run.SetResourceReference(BackgroundProperty, "colorBrush2");

Paragraph paragraph = new Paragraph(run);

this.flowDocument.Blocks.Add(paragraph);

Expected Result: Run appears with foreground color and background color as defined in app.xaml above.

Actual Result: Foreground color works (appears orange), but background remains transparent.

Why doesn't binding the run's background to a resource work, like it does with foreground??? I tried adding the run and paragraph to the FlowDocument first and then binding, but the result was the same.

Answer 1

The reason is that BackgroundProperty needs to be clarified. This is what you want:

        Run run = new Run("My name is Bob!");
        run.SetResourceReference(Run.ForegroundProperty, "colorBrush1");
        run.SetResourceReference(Run.BackgroundProperty, "colorBrush2");

A real mystery is why just writing "ForegroundProperty" works.