Why are there self-duplicating curly braces in a saved WPF RichTextBox?

Question

Our tester cast braces on our persistent WPF RichTextBoxes. When you save and reopen, magic more curly braces appear.

I cut the problem / code down.

<Window x:Class="WpfApplication1.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Window1" Height="300" Width="300">
<Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="*"></RowDefinition>
        <RowDefinition Height="Auto"></RowDefinition>
        <RowDefinition Height="*"></RowDefinition>
    </Grid.RowDefinitions>

    <RichTextBox x:Name="rtb1" />
    <Button Grid.Row="1" Click="Button_Click">Draw a fish</Button>
    <RichTextBox x:Name="rtb2" Grid.Row="2"/>
</Grid>
</Window>

Two rich text boxes. When the button is pressed, the lower part is set to the result of the first after saving and restoring.

namespace WpfApplication1
{
    /// <summary>
    /// Interaction logic for Window1.xaml
    /// </summary>
    public partial class Window1 : Window
    {
        public Window1()
        {
            InitializeComponent();

            rtb1.Document = new FlowDocument(new Paragraph(new Run("{")));
        }


        public static FlowDocument CreateFlowDocumentFromByteArray(byte[] byteArray)
        {
            return (FlowDocument)XamlReader.Load(new MemoryStream(byteArray));
        }

        public static byte[] CreateByteArrayFromFlowDocument(FlowDocument flowDocument)
        {
            MemoryStream mStream = new MemoryStream();
            XmlWriterSettings settings = new XmlWriterSettings();
            settings.Indent = false;
            settings.OmitXmlDeclaration = true;
            XamlDesignerSerializationManager dsm = new XamlDesignerSerializationManager(XmlWriter.Create(mStream, settings));
            dsm.XamlWriterMode = XamlWriterMode.Value;
            XamlWriter.Save(flowDocument, dsm);
            mStream.Close();
            return mStream.ToArray();
        }

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            rtb2.Document = CreateFlowDocumentFromByteArray(CreateByteArrayFromFlowDocument(rtb1.Document));
        }

    }
}

Why is this happening? How to stop it?

Answer 1

I'll run the code in more detail tonight, but will this happen when the braces are not at the beginning of the text? For example, if your launch was "Hello {World}", is it still doing this?

, , , WPF, . :

<Button Content="{Hello}" />

, :

<Button Content="{}{Hello}" />

XamlReader.Load, {} XAML, . . , XAML?