Q:

Converter to show description of an enum, and convert back to enum value on selecting an item from combo box in wpf

I am using an enum to enlist values in my combobox.
I want to write a converter that would show the "description" of the selected enum value. And, when selected, it would return the enum value.
Most of the converters online have not implemented the ConvertBack() method (which is why I am posting here).
Thanks in advance.

A:

Here is ConvertBack method:
public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
    return value;
}

Full Converter Code:
public class EnumConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        if (value == null) return DependencyProperty.UnsetValue;

        return GetDescription((Enum)value);
    }

    public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        return value;
    }

    public static string GetDescription(Enum en)
    {
        Type type = en.GetType();
        MemberInfo[] memInfo = type.GetMember(en.ToString());
        if (memInfo != null && memInfo.Length > 0)
        {
            object[] attrs = memInfo[0].GetCustomAttributes(typeof(DescriptionAttribute), false);
            if (attrs != null && attrs.Length > 0)
            {
                return ((DescriptionAttribute)attrs[0]).Description;
            }
        }
        return en.ToString();
    }
}

EDIT
Here is my ComboBox XAML:
<ComboBox ItemsSource="{Binding SampleValues}" 
          SelectedItem="{Binding SelectedValue, Converter={StaticResource enumConverter}}">
    <ComboBox.ItemTemplate>
        <DataTemplate>
            <TextBlock Text="{Binding Path=., Converter={StaticResource enumConverter}}" />
        </DataTemplate>
    </ComboBox.ItemTemplate>
</ComboBox>

A:

I know this is an old question, but for some reason, this is rather complicated, even though it seems like it'd be a pretty common task (I'm currently doing this on a UWP app). Using a combination of the accepted answer, some other items I found, and a bit of my own work, here's the simplest way I've found to accomplish this menial task. In short:

Define your enum along w/ setting the description in the Display attribute
Create a converter that converts from an enum value to the description
In your viewmodel, expose a collection of enum values from which to choose, the selected enum value, then initialize those
Define a couple of handy enum extension methods
Finally, some simple binding to the ComboBox, just overriding its ItemTemplate to use the converter.

Enum
public enum EnumOptions
{
    [Display(Description = "Option 1")]
    OptionOne= 1,
    [Display(Description = "Option 2")]
    OptionTwo,
    [Display(Description = "Option 3")]
    OptionThree
}

Converter
public class EnumToDisplayConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, string language)
    {
        var enumValue = value as Enum;

        return enumValue == null ? DependencyProperty.UnsetValue : enumValue.GetDescriptionFromEnumValue();
    }

    public object ConvertBack(object value, Type targetType, object parameter, string language)
    {
        return value;
    }
}

Viewmodel (partial)
public IReadOnlyList<EnumOptions> Options { get; }

private EnumOptions _selectedOption;

public EnumOptions SelectedOption
{
    get { return _selectedOption; }
    set
    {
        _selectedOption = value;
        OnPropertyChanged(() => SelectedOption);
    }
}

// Initialization in constructor
Options = EnumExtensions.GetValues<EnumOptions>().ToArray();
// If you want to set a default.
SelectedOption = Options[0];

Extensions
public static class EnumExtensions
{
    public static string GetDescriptionFromEnumValue(this Enum value)
    {
        var attribute = value.GetType()
            .GetField(value.ToString())
            .GetCustomAttributes(typeof(DisplayAttribute), false)
            .SingleOrDefault() as DisplayAttribute;
        return attribute == null ? value.ToString() : attribute.Description;
    }

    /// <summary>
    /// Enumerates all enum values
    /// </summary>
    /// <typeparam name="T">Enum type</typeparam>
    /// <returns>IEnumerable containing all enum values</returns>
    /// <see cref="http://stackoverflow.com/questions/972307/can-you-loop-through-all-enum-values"/>
    public static IEnumerable<T> GetValues<T>()
    {
        return Enum.GetValues(typeof (T)).Cast<T>();
    }
}

XAML (partial)
<TextBlock Grid.Row="1">Choose an option</TextBlock>
<ComboBox Grid.Row="2"
          ItemsSource="{Binding Options}"
          SelectedItem="{Binding SelectedOption, Mode=TwoWay}">
    <ComboBox.ItemTemplate>
        <DataTemplate>
            <TextBlock Text="{Binding Converter={StaticResource EnumToDisplayConverter}}"></TextBlock>
        </DataTemplate>
    </ComboBox.ItemTemplate>
</ComboBox>

