RichEditBox (UWP) ignores font and foreground when setting Rtf text

Question

I'm working with a RichEditBox and I'm having some problems saving and restoring the Rtf text.

Here's a sample Rtf text I've exported, as you can see there are the different foreground colors and font families saved correctly (I've manually indented it to make it easier to read):

{\rtf1\fbidis\ansi\ansicpg1252\deff0\nouicompat\deflang1040
    {\fonttbl{\f0\fnil\fcharset0 Segoe UI;}
    {\f1\fnil\fcharset0 Brush Script MT;}
    {\f2\fnil\fcharset0 Impact;}
    {\f3\fnil Segoe UI;}}
{\colortbl ;\red9\green105\blue192;\red0\green0\blue0;\red76\green152\blue25;\red208\green52\blue56;}
{\*\generator Riched20 10.0.14393}\viewkind4\uc1 
\pard\ltrpar\tx720\cf1\b\i\f0\fs23 Test\cf2\b0\i0\par
\pard\ltrpar\li320\qc\tx720\cf3\strike\f1\fs40 Some color\cf2\strike0\f0\fs23\par
\pard\ltrpar\tx720\cf4\f2 Hello!\cf2\f0\par
\f3\par
\f0\lang1033\par
\f3\par
\par
\pard\ltrpar\tx720\fs23\par
}

Problem: I call

EditBox.Document.SetText(TextSetOptions.FormatRtf, myRtfString);

And the text is loaded in the control, but the font families and the foreground colors are completely ignored. I've already tried calling:

EditBox.Document.ApplyDisplayUpdates();

It doesn't solve the issue. I mean, why is it that all the other paragraph/character options are restored correctly, but just the font families and foreground colors are ignored? Am I missing something here? Thanks!

Edit: this is the custom Style I'm using for the RichEditBox:

<Style TargetType="RichEditBox" x:Key="CustomRtfEditBoxStyle">
    <Setter Property="MinWidth" Value="{ThemeResource TextControlThemeMinWidth}" />
    <Setter Property="MinHeight" Value="{ThemeResource TextControlThemeMinHeight}" />
    <Setter Property="Foreground" Value="{ThemeResource TextControlForeground}" />
    <Setter Property="Background" Value="{ThemeResource TextControlBackground}" />
    <Setter Property="SelectionHighlightColor" Value="{ThemeResource TextControlSelectionHighlightColor}" />
    <Setter Property="BorderBrush" Value="{ThemeResource TextControlBorderBrush}" />
    <Setter Property="BorderThickness" Value="{ThemeResource TextControlBorderThemeThickness}" />
    <Setter Property="FontFamily" Value="{ThemeResource ContentControlThemeFontFamily}" />
    <Setter Property="FontSize" Value="{ThemeResource ControlContentThemeFontSize}" />
    <Setter Property="ScrollViewer.HorizontalScrollMode" Value="Auto" />
    <Setter Property="ScrollViewer.VerticalScrollMode" Value="Auto" />
    <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Auto" />
    <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Auto" />
    <Setter Property="ScrollViewer.IsDeferredScrollingEnabled" Value="False" />
    <Setter Property="TextWrapping" Value="Wrap" />
    <Setter Property="Padding" Value="{ThemeResource TextControlThemePadding}" />
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="RichEditBox">
                <Grid>
                    <VisualStateManager.VisualStateGroups>
                        <VisualStateGroup x:Name="CommonStates">
                            <VisualState x:Name="Disabled" />
                            <VisualState x:Name="Normal" />
                            <VisualState x:Name="PointerOver" />
                            <VisualState x:Name="Focused" />
                            <VisualState x:Name="UnFocused" />
                        </VisualStateGroup>
                    </VisualStateManager.VisualStateGroups>
                    <Grid.RowDefinitions>
                        <RowDefinition Height="Auto" />
                        <RowDefinition Height="*" />
                    </Grid.RowDefinitions>
                    <Border x:Name="BorderElement"
                            Grid.Row="1"
                            Background="{ThemeResource TextControlBackgroundFocused}"
                            BorderThickness="0"
                            Grid.ColumnSpan="2"
                            Grid.RowSpan="1" />
                    <ContentPresenter x:Name="HeaderContentPresenter"
                                    x:DeferLoadStrategy="Lazy"
                                    Visibility="Collapsed"
                                    Grid.Row="0"
                                    Margin="0,0,0,8"
                                    Grid.ColumnSpan="2"
                                    Content="{TemplateBinding Header}"
                                    ContentTemplate="{TemplateBinding HeaderTemplate}"
                                    FontWeight="Normal" />
                    <ScrollViewer x:Name="ContentElement"
                                  RequestedTheme="Light"
                                Grid.Row="1"
                                HorizontalScrollMode="{TemplateBinding ScrollViewer.HorizontalScrollMode}"
                                HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}"
                                VerticalScrollMode="{TemplateBinding ScrollViewer.VerticalScrollMode}"
                                VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}"
                                IsHorizontalRailEnabled="{TemplateBinding ScrollViewer.IsHorizontalRailEnabled}"
                                IsVerticalRailEnabled="{TemplateBinding ScrollViewer.IsVerticalRailEnabled}"
                                IsDeferredScrollingEnabled="{TemplateBinding ScrollViewer.IsDeferredScrollingEnabled}"
                                Margin="{TemplateBinding BorderThickness}"
                                Padding="{TemplateBinding Padding}"
                                IsTabStop="False"
                                ZoomMode="Disabled"
                                AutomationProperties.AccessibilityView="Raw" />
                    <ContentControl x:Name="PlaceholderTextContentPresenter"
                                    Grid.Row="1"
                                    Margin="{TemplateBinding BorderThickness}"
                                    Padding="{TemplateBinding Padding}"
                                    IsTabStop="False"
                                    Grid.ColumnSpan="2"
                                    Content="{TemplateBinding PlaceholderText}"
                                    IsHitTestVisible="False" />
                </Grid>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

Answer 1

This issue currently cannot be reproduced in newest windows 10 build 14393 by code as follows:

XAML Code

... mc:Ignorable="d" Loaded="Page_Loaded">
<StackPanel Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
   <RichEditBox x:Name="EditBox"  Height="400" Margin="40"   >
   </RichEditBox> 
</StackPanel>

Code behind:

private void Page_Loaded(object sender, RoutedEventArgs e)
{
    string myRtfString = @"{\rtf1\fbidis\ansi\ansicpg1252\deff0\nouicompat\deflang1040
 {\fonttbl{\f0\fnil\fcharset0 Segoe UI;}
 {\f1\fnil\fcharset0 Brush Script MT;}
 {\f2\fnil\fcharset0 Impact;}
 {\f3\fnil Segoe UI;}}
 {\colortbl ;\red9\green105\blue192;\red0\green0\blue0;\red76\green152\blue25;\red208\green52\blue56;}
 {\*\generator Riched20 10.0.14393}\viewkind4\uc1 
 \pard\ltrpar\tx720\cf1\b\i\f0\fs23 Test\cf2\b0\i0\par
 \pard\ltrpar\li320\qc\tx720\cf3\strike\f1\fs40 Some color\cf2\strike0\f0\fs23\par
 \pard\ltrpar\tx720\cf4\f2 Hello!\cf2\f0\par
 \f3\par
 \f0\lang1033\par   
 \f3\par
 \par
 \pard\ltrpar\tx720\fs23\par
 }";
    EditBox.Document.SetText(TextSetOptions.FormatRtf, myRtfString);
} 

If you still want a workaround in your environment, please try to find the following code which is under “Focused ViewState” in the style of RichEditTextBox and comment it out. For more details about this please reference this thread.

 <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentElement">
     <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlForegroundChromeBlackHighBrush}"/>
 </ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="RequestedTheme" Storyboard.TargetName="ContentElement">
    <DiscreteObjectKeyFrame KeyTime="0" Value="Light"/>
</ObjectAnimationUsingKeyFrames>

And the result on my side: