How to bind a TextBlock to a resource containing formatted text?

Question

I have a TextBlock in my WPF window.

 
     Some formatted text.
 

When it is r

Answer 1

EDIT:

This line,

is a bad approach to accesing the Project.Properties.Resources namespace. It causes awkward glitches when recompiling.

Much better to use x:Static to do somthing like this,

Text="{x:Static props:Resources.SomeText}"

in your binding. Thx to Ben

---

Okay, this is how I did it. It's not perfect but it works.

Remember, there is a project resource called FormattedText.

cs:

// TextBlock with a bindable InlineCollection property.

// Type is List(Inline) not InlineCollection becuase
// InlineCollection makes the IDE xaml parser complain
// presumably this is caused by an inherited attribute.

public class BindableTextBlock : TextBlock
{
    public static readonly DependencyProperty InlineCollectionProperty =
        DependencyProperty.Register(
            "InlineCollection",
            typeof(List),
            typeof(BindableTextBlock),
            new UIPropertyMetadata(OnInlineCollectionChanged));

    private static void OnInlineCollectionChanged(DependencyObject sender,
        DependencyPropertyChangedEventArgs e)
    {
        BinableTextBlock instance = sender as BindableTextBlock;

        if (instance != null)
        {
            List newText = e.NewValue as List;
            if (newText != null)
            {
                // Clear the underlying Inlines property
                instance.Inlines.Clear();
                // Add the passed List to the real Inlines
                instance.Inlines.AddRange(newText.ToList());
            }
        }
    }

    public List InlineCollection
    {
        get
        {
            return (List)GetValue(InlineCollectionProperty);
        }
        set
        {
            SetValue(InlineCollectionProperty, value);
        }
    }
}

// Convertor between a string of xaml with implied run elements
// and a generic list of inlines

[ValueConversion(typeof(string), typeof(List))]
public class StringInlineCollectionConvertor : IValueConverter
{
    public object Convert(object value, 
        Type targetType, 
        object parameter, 
        System.Globalization.CultureInfo culture)
    {
        string text = value as String;

        // a surrogate TextBlock to host an InlineCollection
        TextBlock results = new TextBlock();

        if (!String.IsNullOrEmpty(text))
        {
            //Arbritary literal acting as a replace token, 
            //must not exist in the empty xaml definition.
            const string Replace = "xxx";

            // add a dummy run element and replace it with the text
            results.Inlines.Add(new Run(Replace));
            string resultsXaml = XamlWriter.Save(results);
            string resultsXamlWithText = resultsXaml.Replace(Replace, text);

            // deserialise the xaml back into our TextBlock
            results = XamlReader.Parse(resultsXamlWithText) as TextBlock;
        }
        return results.Inlines.ToList();
    }

    // Not clear when this will be called but included for completeness

    public object ConvertBack(
        object value, 
        Type targetType, 
        object parameter, 
        System.Globalization.CultureInfo culture)
    {
        String results = String.Empty;

        InlineCollection inlines = value as InlineCollection;
        if (inlines != null)
        {
            //read the xaml as xml and return the "content"
            var reader = 
                XElement.Parse(XamlWriter.Save(inlines)).CreateReader();
            reader.MoveToContent();
            results = reader.ReadInnerXml();
        }
        return results;
    }
}

xaml:

I made 2 classes. A sub-classed TextBlock with a "bindable" InlineCollection and an IValueConverter to convert the collection from and to a String.

Using InlineCollection directly as the type of the property made VS2010 complain, although the code still ran fine. I changed to a generic list of Inlines. I assume that there is an inherited attribute telling VS that the InlineCollection has no constructor.

I tryed making the InlineCollection property the BindableTextBlock's ContentProperty but ran into issues and out of time. Please feel free to take the next step and tell me about it.

I apologise for any errata but this code had to be transcribed and sanitised.

If there is a better way of doing this, surely there must be, please tell me that too. Wouldn't it be nice if this functionality was built in or, have I missed something?