Extended WPF Toolkit RichTextBox display text vertically

Question

I'm trying to bind a rich content (RTF format) to a rich text box (of Extended WPF Toolkit) via its Text property like this

<extToolkit:RichTextBox x:Name="rtbKIContent" Margin="8,8,8,8" 
                                    IsEnabled="{Binding IsEditable}"
                                    Text="{Binding Content}">
                <extToolkit:RichTextBox.TextFormatter>
                    <extToolkit:RtfFormatter></extToolkit:RtfFormatter>

                </extToolkit:RichTextBox.TextFormatter>
                <extToolkit:RichTextBoxFormatBarManager.FormatBar>
                    <extToolkit:RichTextBoxFormatBar />
                </extToolkit:RichTextBoxFormatBarManager.FormatBar>
</extToolkit:RichTextBox>

Sometimes it works just fine, but there are circumstances that they just display the text vertically like this.

I don't know what's wrong with it...What should I do to make it display text from left to right like normal?

Answer 1

If you add a width to the RichTextBox, it should fix it.

I did this so it binds to the parent.

Width="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType=Grid, AncestorLevel=1}, Path=ActualWidth}"

Note you will have to determine AncestorType for you. But you can do this too. Width="100"