Binding to display name attribute of enum in xaml

Question

I have the following enum:

public enum ViewMode
{
    [Display(Name = "Neu")]
    New,
    [Display(Name = "Bearbeiten")]
    Edit,
    [Display(Name = "Suchen")]
    Search
}

I'm using xaml and databinding to show the enum in my window:

<Label Content="{Binding CurrentViewModel.ViewMode}" Grid.Column="2" VerticalContentAlignment="Bottom" Height="43" HorizontalContentAlignment="Right"/>

But this doesn't show the display name attribute. How can I do so?

In my viewModel I can get the display name attribute by using an extension method:

public static class EnumHelper
{
    /// <summary>
    /// Gets an attribute on an enum field value
    /// </summary>
    /// <typeparam name="T">The type of the attribute you want to retrieve</typeparam>
    /// <param name="enumVal">The enum value</param>
    /// <returns>The attribute of type T that exists on the enum value</returns>
    public static T GetAttributeOfType<T>(this Enum enumVal) where T : System.Attribute
    {
        var type = enumVal.GetType();
        var memInfo = type.GetMember(enumVal.ToString());
        var attributes = memInfo[0].GetCustomAttributes(typeof(T), false);
        return (attributes.Length > 0) ? (T)attributes[0] : null;
    }
}

Usage is string desc = myEnumVariable.GetAttributeOfType<DescriptionAttribute>().Description;. However, this doesn't help in XAML.

Answer 1

Create a class implementing the System.Windows.Data.IValueConverter interface and specify it as the binding's converter. Optionally, for easier usage, you can create a "provider" class implementing System.Windows.Markup.MarkupExtension (actually you can do both with just one class). Your end result could resemble this example:

public class MyConverter : MarkupExtension, IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        return ((Enum)value).GetAttributeOfType<DisplayAttribute>().Name;
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        throw new NotSupportedException();
    }

    public override object ProvideValue(IServiceProvider serviceProvider)
    {
        return this;
    }
}

And then in XAML:

<Label Content="{Binding CurrentViewModel.ViewMode, Converter={local:MyConverter}}" Grid.Column="2" VerticalContentAlignment="Bottom" Height="43" HorizontalContentAlignment="Right"/>