WPF

<Window.Resources>
    <!--  Storyboard as a window resource  -->
    <Storyboard
        x:Key="NB"
        x:Name="NB_resource"
        Completed="NB_resource_Completed"
        RepeatBehavior="5x">
        <ObjectAnimationUsingKeyFrames
            Storyboard.TargetName="NB_image"
            Storyboard.TargetProperty="Source"
            Duration="0:0:1.2">
            <DiscreteObjectKeyFrame KeyTime="0:0:0">
                <DiscreteObjectKeyFrame.Value>
                    <BitmapImage UriSource="pack://application:,,,/CircleSurrogateButton;component/Images/NB_00.png" />
                </DiscreteObjectKeyFrame.Value>
            </DiscreteObjectKeyFrame>
            <DiscreteObjectKeyFrame KeyTime="0:0:.3">
                <DiscreteObjectKeyFrame.Value>
                    <BitmapImage UriSource="pack://application:,,,/CircleSurrogateButton;component/Images/NB_01.png" />
                </DiscreteObjectKeyFrame.Value>
            </DiscreteObjectKeyFrame>

            <DiscreteObjectKeyFrame KeyTime="0:0:.6">
                <DiscreteObjectKeyFrame.Value>
                    <BitmapImage UriSource="pack://application:,,,/CircleSurrogateButton;component/Images/NB_02.png" />
                </DiscreteObjectKeyFrame.Value>
            </DiscreteObjectKeyFrame>
            <DiscreteObjectKeyFrame KeyTime="0:0:.9">
                <DiscreteObjectKeyFrame.Value>
                    <BitmapImage UriSource="pack://application:,,,/CircleSurrogateButton;component/Images/NB_03.png" />
                </DiscreteObjectKeyFrame.Value>
            </DiscreteObjectKeyFrame>
        </ObjectAnimationUsingKeyFrames>
    </Storyboard>
</Window.Resources>

<EventTrigger RoutedEvent="PreviewMouseLeftButtonDown">
 <BeginStoryboard Storyboard="{DynamicResource NB}" />
 </EventTrigger>

<DataTrigger Binding="{Binding Start_Storyboard}" Value="true">
        <DataTrigger.EnterActions>
            <BeginStoryboard Storyboard="{DynamicResource NB}"/>
        </DataTrigger.EnterActions>
 </DataTrigger>

public static void Install()
{
    InstallIIS();
    InstallASPDotNet();
}

private static void InstallIIS()
{
    InstallFeature("IIS", "/Online /Enable-Feature /FeatureName:IIS-DefaultDocument /All");
}

private static void InstallASPDotNet()
{
    InstallFeature("ASP.Net", "/Online /Enable-Feature /FeatureName:IIS-ASPNET45 /All");
}

private static void InstallFeature(string featureName, string args)
{
    try
    {
        // Raise the task changed event so the UI shows what is installing
        CurrentTaskChanged($"Installing {featureName}");

        string dism = Path.Combine(Environment.ExpandEnvironmentVariables("%windir%"), "system32", "dism.exe");
        if (Environment.Is64BitOperatingSystem && !Environment.Is64BitProcess)
        {
            dism = Path.Combine(Environment.ExpandEnvironmentVariables("%windir%"), "sysnative", "dism.exe");
        }

        var process = new Process();
        var startInfo = new ProcessStartInfo
        {
            UseShellExecute = false,
            CreateNoWindow = false,
            RedirectStandardOutput = true,
            FileName = dism,
            Arguments = args
        };

        process.StartInfo = startInfo;
        process.OutputDataReceived += (sender, e) => HandleDISMOutput(e.Data);
        process.Start();
        process.BeginOutputReadLine();
        process.StartInfo.Verb = "runas";
        process.WaitForExit();
        process.CancelOutputRead();
        process.Close();
    }
    catch (Exception e)
    {
        throw;
    }
}

private static void HandleDISMOutput(object data)
{
    if (data != null)
    {
        var info = data.ToString();

        if (info.Contains("%"))
        {
            // Parse out the percent digits
            info = info.Replace('[', ' ');
            info = info.Replace(']', ' ');
            info = info.Replace('=', ' ');
            info = info.Replace(" ", "");
            info = info.Replace("%", "");

            double.TryParse(info, out double percent);

            // Raise the percent completed event to update the progress bar in the UI
            ProgressUpdated(percent);
        }
    }
}

private void InstallExecuted()
{
    RemoteServicesInstaller.CurrentTaskChanged += CurrentTaskChanged;
    RemoteServicesInstaller.ProgressUpdated += ProgressUpdated;
    RemoteServicesInstaller.Install();
}

private void CurrentTaskChanged(string action)
{
    InstallAction = action;
    Debug.Print(action);
}

private void ProgressUpdated(double percent)
{
    InstallPercent = percent;
    Debug.Print(percent.ToString());
}

Google Translate:

Hello,
I have a RichTextBox in which there is a FlowDocument

I create a table by code

the table is displayed correctly
I save it in RTF.
I lose the formatting
only the Background is good

Thank you for your reply

a piece of code

private void button2_Click_1(object sender, RoutedEventArgs e)
        {
          
             Table T = new Table();
            
            myFlowDoc.Blocks.Add(T);
            T.CellSpacing = 1;
        
          
            for (int x = 0;x<5;x++) { T.Columns.Add(new TableColumn()); }
            T.Columns[0].Background = Brushes.Beige;
            T.Columns[0].Width = new GridLength(200);
            T.Columns[1].Width = new GridLength(150);
            T.Columns[2].Width = new GridLength(60);
            T.Columns[3].Width = new GridLength(100);
            T.Columns[4].Width = new GridLength(100);


            T.BorderThickness = new Thickness(1);
            T.BorderBrush = Brushes.Red;
           

            T.RowGroups.Add(new TableRowGroup());
            T.RowGroups[0].Rows.Add(new TableRow());  // ajout titre

            TableRow currentRow = T.RowGroups[0].Rows[0];
            currentRow.FontWeight = FontWeights.Bold;

            currentRow.Background = Brushes.Silver;    /// ok
            
            currentRow.FontSize = 20;
 

            TableCell TC = new TableCell();
           
            currentRow.Cells.Add(TC);
            TC.TextAlignment = TextAlignment.Center;
            myParagraph = new Paragraph(new Run("Résultat des mesures "));
       

            TC.Blocks.Add(myParagraph);