Question

I had databinding set up like this:

ItemsSource="{Binding Source={my:Enumeration {x:Type credit:OccupationCategory}}}"
                      DisplayMemberPath="Description"
                      SelectedValue="{Binding EmplType}"
                      SelectedValuePath="Value"/>

and it worked really well. Do to a change in the larger software design I can no longer have anything that generates an INotifyPropertyChanged Event so that type of databinding doesn’t work. Instead I am manually setting the selectedIndex and building the options from code like this:

ItemsSource="{Binding Source={StaticResource ResidenceOwnershipType}}"/>

which references

<UserControl.Resources>
    <ObjectDataProvider x:Key="ResidenceOwnershipType" MethodName="GetValues" ObjectType="{x:Type System:Enum}" >
        <ObjectDataProvider.MethodParameters>
            <x:Type TypeName="credit:ResidenceOwnershipType" />
        </ObjectDataProvider.MethodParameters>
    </ObjectDataProvider>
</UserControl.Resources>

That works as far as the building of the list options is concerned and the linking of all of my data, but I can’t get the comboboxes to show the description tag in the enumeration instead of the actual text.

I’ve tried something like this:

DisplayMemberPath="Description"

but that wasn’t correct. How would I go about doing this?

EDIT:

My Enum:

[DataContract]
public enum ResidenceOwnershipType
{
    [Description("")]
    None = 0,
    [Description("Owns Home Outright")]
    OwnsHomeOutright = 1,
    [Description("Buying Home")]
    BuyingHome = 2,
    [Description("Renting/Leasing")] //Weird order here reflects RouteOne website
    RentingLeasing = 4,
    [Description("Living w/Relatives")]
    LivingWithRelatives = 3,
    [Description("Owns/Buying Mobile Home")]
    MobileHome = 5,
    [Description("Unknown")]
    Unknown = 6
}

Answer 1

If you keep this ItemsSource you will have to define a custom ItemTemplate as the DisplayMemberPath is just a path via which you will not be able to retrieve the description.

As for what the template should look like: You can bind a TextBlock to the enum value (the current DataContext) and pipe that through a ValueConverter using Binding.Converter. The code would just be some reflection to retrieve the Description (GetType, GetCustomAttributes etc.)

Alternatives are a custom method that return a usable collection right away (and is used in the ObjectDataProvider) or a custom markup extension which does the same thing.

---

Method example if we are talking about a ComponentModel.DescriptionAttribute:

public static class EnumUtility
{
    // Might want to return a named type, this is a lazy example (which does work though)
    public static object[] GetValuesAndDescriptions(Type enumType)
    {
        var values = Enum.GetValues(enumType).Cast<object>();
        var valuesAndDescriptions = from value in values
                                    select new
                                        {
                                            Value = value,
                                            Description = value.GetType()
                                                .GetMember(value.ToString())[0]
                                                .GetCustomAttributes(true)
                                                .OfType<DescriptionAttribute>()
                                                .First()
                                                .Description
                                        };
        return valuesAndDescriptions.ToArray();
    }
}

<ObjectDataProvider x:Key="Data" MethodName="GetValuesAndDescriptions"
                    ObjectType="local:EnumUtility">
    <ObjectDataProvider.MethodParameters>
        <x:TypeExtension TypeName="local:TestEnum" />
    </ObjectDataProvider.MethodParameters>
</ObjectDataProvider>

<ListBox ItemsSource="{Binding Source={StaticResource Data}}"
         DisplayMemberPath="Description"
         SelectedValuePath="Value"/>