During an informal discussion yesterday, the question of displaying text vertically (i.e., letters stacked on top of each other instead of side-by-side) came up and I offhandedly said it would be pretty easy to do. Later on, I got curious about just how accurate my claim was, so I spent a bit of time on the bus coding up a quick demonstration of what I had in mind. What I ended up with is a simple example, but it's enough that I feel like my flippant estimate wasn't so far off after all. :)

VerticalTextBlock is a simple Control subclass that runs on both Silverlight and WPF. The following XAML (in which the optional parts are italicized):

<local:VerticalTextBlock
    Text="Hello world"
    FontFamily="Arial"
    FontSize="12"
    FontWeight="Bold"
    Background="Orange"/>

Renders as follows (Silverlight on the left, WPF on the right):

VerticalTextBlock Demonstration

The implementation is quite simple: VerticalTextBlock exposes a Text property of type string, the VerticalTextBlock Template contains a TextBlock, and that TextBlock is populated with a series of LineBreak-separated Runs containing one character each.

Here's the complete code that compiles for both platforms:

using System.IO;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Markup;

namespace VerticalTextBlockSample
{
    public class VerticalTextBlock : Control
    {
        public VerticalTextBlock()
        {
            IsTabStop = false;
            var templateXaml =
                @"<ControlTemplate " +
#if SILVERLIGHT
                    "xmlns='http://schemas.microsoft.com/client/2007' " +
#else
                    "xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation' " +
#endif
                    "xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'>" +
                    "<Grid Background=\"{TemplateBinding Background}\">" +
                        "<TextBlock x:Name=\"TextBlock\" TextAlignment=\"Center\"/>" +
                    "</Grid>" +
                "</ControlTemplate>";
#if SILVERLIGHT
            Template = (ControlTemplate)XamlReader.Load(templateXaml);
#else
            using(var stream = new MemoryStream(Encoding.UTF8.GetBytes(templateXaml)))
            {
                Template = (ControlTemplate)XamlReader.Load(stream);
            }
#endif
        }

        public override void OnApplyTemplate()
        {
            base.OnApplyTemplate();
            _textBlock = GetTemplateChild("TextBlock") as TextBlock;
            CreateVerticalText(_text);
        }

        private string _text { get; set; }
        private TextBlock _textBlock { get; set; }

        public string Text
        {
            get { return (string)GetValue(TextProperty); }
            set { SetValue(TextProperty, value); }
        }
        public static readonly DependencyProperty TextProperty = DependencyProperty.Register(
            "Text", typeof(string), typeof(VerticalTextBlock), new PropertyMetadata(OnTextChanged));
        private static void OnTextChanged(DependencyObject o, DependencyPropertyChangedEventArgs e)
        {
            ((VerticalTextBlock)o).OnTextChanged((string)(e.NewValue));
        }
        private void OnTextChanged(string newValue)
        {
            CreateVerticalText(newValue);
        }

        private void CreateVerticalText(string text)
        {
            _text = text;
            if (null != _textBlock)
            {
                bool first = true;
                foreach (var c in _text)
                {
                    if (!first)
                    {
                        _textBlock.Inlines.Add(new LineBreak());
                    }
                    _textBlock.Inlines.Add(new Run { Text = c.ToString() });
                    first = false;
                }
            }
        }
    }
}

At the end of the day, VerticalTextBlock is a simple control I wrote to keep myself honest. :) I figured it could be useful to others, so I'm posting about it and attaching a ZIP file with the complete solution+projects so anyone who's interested can try it out!