Binding to Enumerations

Every now and then, you find yourself needing to bind some control or the other to the values of an enumeration, such as System.DayOfWeek. You'd think this would be fairly simple, but it's actually trickier than you think.

I am fortunate to work with Paul Jackson, who's a very clever chap, especially when it comes to WPF. Paul blogged about the ins and outs of binding to enumerations some time ago and I keep finding myself having to search for it, so I thought I'd add it to my own blog for safe keeping.

To summarise, you need to do the following:

1. Add the appropriate XML namespace.
2. Add an ObjectDataProvider with the MethodName set to GetValues.
3. Set the ItemsSource property of your control.

<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:sys="clr-namespace:System;assembly=mscorlib" ...>
    <Window.Resources>
        <ObjectDataProvider x:Key="DayValues"
                            MethodName="GetValues"
                            ObjectType="{x:Type sys:Enum}">
            <ObjectDataProvider.MethodParameters>
                <x:Type TypeName="sys:DayOfWeek" />
            </ObjectDataProvider.MethodParameters>
        </ObjectDataProvider>
    </Window.Resources>
    <Grid>
        ...
        <ComboBox x:Name="_days"
                  ItemsSource="{Binding Source={StaticResource DayValues}}" />
        ...
    </Grid>
</Window>

What Paul's article doesn't mention is how to specify the SelectedValue. The following code example shows how to set the SelectedValue for our ComboBox above to be DayOfWeek.Monday.

<ComboBox x:Name="_days"
          ItemsSource="{Binding Source={StaticResource DayValues}}"
          SelectedValue="{x:Static sys:DayOfWeek.Monday}" />

Thanks Paul :).