Databinding an enum property to a ComboBox in WPF

Question

As an example take the following code:

public enum ExampleEnum { FooBar, BarFoo }

public class ExampleClass : INotifyPropertyChanged
{
    private ExampleEnum example;

    public ExampleEnum ExampleProperty 
    { get { return example; } { /* set and notify */; } }
}

I want a to databind the property ExampleProperty to a ComboBox, so that it shows the options "FooBar" and "BarFoo" and works in mode TwoWay. Optimally I want my ComboBox definition to look something like this:

<ComboBox ItemsSource="What goes here?" SelectedItem="{Binding Path=ExampleProperty}" />

Currently I have handlers for the ComboBox.SelectionChanged and ExampleClass.PropertyChanged events installed in my Window where I do the binding manually.

Is there a better or some kind of canonical way? Would you usually use Converters and how would you populate the ComboBox with the right values? I don't even want to get started with i18n right now.

Edit

So one question was answered: How do I populate the ComboBox with the right values.

Retrieve Enum values as a list of strings via an ObjectDataProvider from the static Enum.GetValues method:

<Window.Resources>
    <ObjectDataProvider MethodName="GetValues"
        ObjectType="{x:Type sys:Enum}"
        x:Key="ExampleEnumValues">
        <ObjectDataProvider.MethodParameters>
            <x:Type TypeName="ExampleEnum" />
        </ObjectDataProvider.MethodParameters>
    </ObjectDataProvider>
</Window.Resources>

This I can use as an ItemsSource for my ComboBox:

<ComboBox ItemsSource="{Binding Source={StaticResource ExampleEnumValues}}"/>

Answer 1

I don't know if it is possible in XAML-only but try the following:

Give your ComboBox a name so you can access it in the codebehind: "typesComboBox1"

Now try the following

typesComboBox1.ItemsSource = Enum.GetValues(typeof(ExampleEnum));

Answer 2

oooops, I stand corrected...

it is possible to do it XAML only, check out this post: http://blogs.msdn.com/wpfsdk/archive/2007/02/22/displaying-enum-values-using-data-binding.aspx

Answer 3

Try using

<ComboBox ItemsSource="{Binding Source={StaticResource ExampleEnumValues}}"
    SelectedValue="{Binding Path=ExampleProperty}" />

Answer 4

I tried the SelectedValue and it works...

Here is my example code and here is a blog post about it!

Answer 5

you can consider something like that:

1. define a style for textblock, or any other control you want to use to display your enum:

       <Style x:Key="enumStyle" TargetType="{x:Type TextBlock}">
           <Setter Property="Text" Value="&lt;NULL&gt;"/>
           <Style.Triggers>
               <Trigger Property="Tag">
                   <Trigger.Value>
                       <proj:YourEnum>Value1<proj:YourEnum>
                   </Trigger.Value>
                   <Setter Property="Text" Value="{DynamicResource yourFriendlyValue1}"/>
               </Trigger>
               <!-- add more triggers here to reflect your enum -->
           </Style.Triggers>
       </Style>
   

2. define your style for ComboBoxItem

       <Style TargetType="{x:Type ComboBoxItem}">
           <Setter Property="ContentTemplate">
               <Setter.Value>
                   <DataTemplate>
                       <TextBlock Tag="{Binding}" Style="{StaticResource enumStyle}"/>
                   </DataTemplate>
               </Setter.Value>
           </Setter>
       </Style>
   

3. add a combobox and load it with your enum values:

           <ComboBox SelectedValue="{Binding Path=your property goes here}" SelectedValuePath="Content">
               <ComboBox.Items>
                   <ComboBoxItem>
                       <proj:YourEnum>Value1</proj:YourEnum>
                   </ComboBoxItem>
               </ComboBox.Items>
           </ComboBox>
   

if your enum is large, you can of course do the same in code, sparing a lot of typing. i like that approach, since it makes localization easy - you define all the templates once, and then, you only update your string resource files.

Answer 6

I explored this and have a solution that you can use (complete with localization) in WPF located here.

Answer 7

Using the ObjectDataProvider (or a collectionviewsource wrapping one for ordering) works well for me, except that if I load an item the SelectedValue reverts to the first item in the enum, instead of the actual value; I want it to use the itemssource and use the data from the item.

Any ideas? IsSynchronizedWithCurrentItems=true, didn't have the desired effect.