WPF ComboBox Binding to Enumeration

Question

I have a Combo Box that has ItemsSource Bound to an Enumeration using ObjectDataProvider, and its SelectedItem Property is bound to a property of a businessobject. For some reason it's binding SelectedItem first and ItemsSource second, therefore overwriting my default on the businessobject property. Any ideas why and possibly a fix? Thanks in Advance.

XAML:

<CollectionViewSource x:Key="Units">
     <CollectionViewSource.Source>
          <ObjectDataProvider MethodName="GetNames" ObjectType="{x:Type sys:Enum}">
               <ObjectDataProvider.MethodParameters>
                    <x:Type TypeName="BO:Unit"/>
               </ObjectDataProvider.MethodParameters>
          </ObjectDataProvider>
     </CollectionViewSource.Source>
</CollectionViewSource>

<ComboBox Grid.Column="1" HorizontalAlignment="Right" Width="80"
          ItemsSource="{Binding Source={StaticResource Units}}" 
          SelectedItem="{Binding Path=Unit}"/>

May be this will help: WPF ObjectDataProvider - Binding Enum to ComboBox — user1802034

Fredrik Hedblad Fredrik Hedblad · Accepted Answer · 2011-02-23T21:47:08

I tried your code and it's working fine so I don't think that order of the Bindings is your problem. One thing I noticed is that you're using GetNames as the MethodName for the ObjectDataProvider so the ComboBox ItemsSource will be a Collection of strings and not of the enum Unit. If this is your intention then the Property Unit should be of type string

Example

public class NamesViewModel
{
    public NamesViewModel(string unit)
    {
        Unit = unit;
    }
    public string Unit
    {
        get;
        set;
    }
}

If you change GetNames to GetValues it'll work for a Property of enum type Unit

Example

public class ValuesViewModel
{
    public ValuesViewModel(Unit unit)
    {
        Unit = unit;
    }
    public Unit Unit
    {
        get;
        set;
    }
}

WPF ComboBox Binding to Enumeration

1 Answers