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    lt ComboBox ItemsSource  What goes here   SelectedItem   Binding Path ExampleProperty     gt    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    lt Window Resources gt       lt ObjectDataProvider MethodName  GetValues          ObjectType   x Type sys Enum           x Key  ExampleEnumValues  gt           lt ObjectDataProvider MethodParameters gt               lt x Type TypeName  ExampleEnum    gt           lt  ObjectDataProvider MethodParameters gt       lt  ObjectDataProvider gt   lt  Window Resources gt    This I can use as an ItemsSource for my ComboBox    lt ComboBox ItemsSource   Binding Source  StaticResource ExampleEnumValues     gt

User · Answer

I ve created an open source CodePlex project that does this   You can download the NuGet package from here    lt enumComboBox EnumComboBox EnumType   x Type demoApplication Status   SelectedValue   Binding Status     gt

User · Answer

you can consider something like that    define a style for textblock  or any other control you want to use to display your enum    lt Style x Key  enumStyle  TargetType   x Type TextBlock   gt       lt Setter Property  Text  Value   amp lt NULL amp gt    gt       lt Style Triggers gt           lt Trigger Property  Tag  gt               lt Trigger Value gt                   lt proj YourEnum gt Value1 lt proj YourEnum gt               lt  Trigger Value gt               lt Setter Property  Text  Value   DynamicResource yourFriendlyValue1    gt           lt  Trigger gt           lt  -- add more triggers here to reflect your enum -- gt       lt  Style Triggers gt   lt  Style gt   define your style for ComboBoxItem   lt Style TargetType   x Type ComboBoxItem   gt       lt Setter Property  ContentTemplate  gt           lt Setter Value gt               lt DataTemplate gt                   lt TextBlock Tag   Binding   Style   StaticResource enumStyle    gt               lt  DataTemplate gt           lt  Setter Value gt       lt  Setter gt   lt  Style gt   add a combobox and load it with your enum values    lt ComboBox SelectedValue   Binding Path your property goes here   SelectedValuePath  Content  gt       lt ComboBox Items gt           lt ComboBoxItem gt               lt proj YourEnum gt Value1 lt  proj YourEnum gt           lt  ComboBoxItem gt       lt  ComboBox Items gt   lt  ComboBox gt     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

User · Answer

I prefer not to use the name of enum in UI  I prefer use different value for user  DisplayMemberPath  and different for value  enum in this case   SelectedValuePath   Those two values can be packed to KeyValuePair and stored in dictionary   XAML   lt ComboBox Name  fooBarComboBox             ItemsSource   Binding Path ExampleEnumsWithCaptions              DisplayMemberPath  Value             SelectedValuePath  Key            SelectedValue   Binding Path ExampleProperty  Mode TwoWay    gt     C   public Dictionary lt ExampleEnum  string gt  ExampleEnumsWithCaptions   get          new Dictionary lt ExampleEnum  string gt                   ExampleEnum FooBar   Foo Bar             ExampleEnum BarFoo   Reversed Foo Bar               ExampleEnum None   Hidden in UI             private ExampleEnum example  public ExampleEnum ExampleProperty       get   return example        set      set and notify           EDIT  Compatible with the MVVM pattern

User · Answer

You can create a custom markup extension   Example of usage   enum Status        Description  Available         Available       Description  Not here right now         Away       Description  I don t have time right now         Busy     At the top of your XAML       xmlns my  clr-namespace namespace to enumeration extension class   and then      lt ComboBox      ItemsSource   Binding Source  my Enumeration  x Type my Status          DisplayMemberPath  Description       SelectedValue   Binding CurrentStatus         SelectedValuePath  Value     gt     And the implementation     public class EnumerationExtension   MarkupExtension         private Type  enumType        public EnumerationExtension Type enumType              if  enumType    null          throw new ArgumentNullException  enumType           EnumType   enumType             public Type EnumType             get   return  enumType          private set                 if   enumType    value            return           var enumType   Nullable GetUnderlyingType value     value           if  enumType IsEnum    false            throw new ArgumentException  Type must be an Enum               enumType   value                     public override object ProvideValue IServiceProvider serviceProvider              var enumValues   Enum GetValues EnumType          return           from object enumValue in enumValues         select new EnumerationMember            Value   enumValue            Description   GetDescription enumValue             ToArray               private string GetDescription object enumValue              var descriptionAttribute   EnumType          GetField enumValue ToString             GetCustomAttributes typeof  DescriptionAttribute   false           FirstOrDefault   as DescriptionAttribute          return descriptionAttribute    null           descriptionAttribute Description           enumValue ToString               public class EnumerationMember             public string Description   get  set          public object Value   get  set

User · Answer

My favorite way to do this is with a ValueConverter so that the ItemsSource and SelectedValue both bind to the same property  This requires no additional properties to keep your ViewModel nice and clean    lt ComboBox ItemsSource   Binding Path ExampleProperty  Converter  x EnumToCollectionConverter   Mode OneTime             SelectedValuePath  Value            DisplayMemberPath  Description            SelectedValue   Binding Path ExampleProperty     gt    And the definition of the Converter   public static class EnumHelper     public static string Description this Enum e          return  e GetType                 GetField e ToString                  GetCustomAttributes typeof DescriptionAttribute   false                FirstOrDefault   as DescriptionAttribute   Description    e ToString            ValueConversion typeof Enum   typeof IEnumerable lt ValueDescription gt     public class EnumToCollectionConverter   MarkupExtension  IValueConverter     public object Convert object value  Type targetType  object parameter  CultureInfo culture          return Enum GetValues value GetType                    Cast lt Enum gt                    Select e   gt  new ValueDescription     Value   e  Description   e Description                     ToList          public object ConvertBack object value  Type targetType  object parameter  CultureInfo culture          return null        public override object ProvideValue IServiceProvider serviceProvider          return this          This converter will work with any enum  ValueDescription is just a simple class with a Value property and a Description property  You could just as easily use a Tuple with Item1 and Item2  or a KeyValuePair with Key and Value instead of Value and Description or any other class of your choice as long as it has can hold an enum value and string description of that enum value

User · Answer

Use ObjectDataProvider    lt ObjectDataProvider x Key  enumValues     MethodName  GetValues  ObjectType   x Type System Enum   gt         lt ObjectDataProvider MethodParameters gt              lt x Type TypeName  local ExampleEnum   gt         lt  ObjectDataProvider MethodParameters gt    lt  ObjectDataProvider gt    and then bind to static resource   ItemsSource   Binding Source  StaticResource enumValues      Find this solution at this blog

User · Answer

Based on the accepted but now deleted answer provided by ageektrapped I created a slimmed down version without some of the more advanced features  All the code is included here to allow you to copy-paste it and not get blocked by link-rot   I use the System ComponentModel DescriptionAttribute which really is intended for design time descriptions  If you dislike using this attribute you may create your own but I think using this attribute really gets the job done  If you don t use the attribute the name will default to the name of the enum value in code   public enum ExampleEnum       Description  Foo Bar      FooBar      Description  Bar Foo      BarFoo      Here is the class used as the items source   public class EnumItemsSource   Collection lt String gt   IValueConverter      Type type     IDictionary lt Object  Object gt  valueToNameMap     IDictionary lt Object  Object gt  nameToValueMap     public Type Type       get   return this type        set         if   value IsEnum          throw new ArgumentException  Type is not an enum     value          this type   value        Initialize                 public Object Convert Object value  Type targetType  Object parameter  CultureInfo culture        return this valueToNameMap value          public Object ConvertBack Object value  Type targetType  Object parameter  CultureInfo culture        return this nameToValueMap value          void Initialize         this valueToNameMap   this type        GetFields BindingFlags Static   BindingFlags Public         ToDictionary fi   gt  fi GetValue null   GetDescription       this nameToValueMap   this valueToNameMap        ToDictionary kvp   gt  kvp Value  kvp   gt  kvp Key       Clear        foreach  String name in this nameToValueMap Keys        Add name          static Object GetDescription FieldInfo fieldInfo        var descriptionAttribute          DescriptionAttribute  Attribute GetCustomAttribute fieldInfo  typeof DescriptionAttribute        return descriptionAttribute    null   descriptionAttribute Description   fieldInfo Name           You can use it in XAML like this    lt Windows Resources gt     lt local EnumItemsSource     x Key  ExampleEnumItemsSource      Type   x Type local ExampleEnum    gt   lt  Windows Resources gt   lt ComboBox   ItemsSource   StaticResource ExampleEnumItemsSource     SelectedValue   Binding ExampleProperty  Converter  StaticResource ExampleEnumItemsSource     gt

User · Answer

This is a DevExpress specific answer based on the top-voted answer by Gregor S   currently it has 128 votes    This means we can keep the styling consistent across the entire application     Unfortunately  the original answer doesn t work with a ComboBoxEdit from DevExpress without some modifications   First  the XAML for the ComboBoxEdit    lt dxe ComboBoxEdit ItemsSource   Binding Source  xamlExtensions XamlExtensionEnumDropdown  x myEnum EnumFilter         SelectedItem   Binding BrokerOrderBookingFilterSelected  Mode TwoWay  UpdateSourceTrigger PropertyChanged       DisplayMember  Description      MinWidth  144  Margin  5       HorizontalAlignment  Left      IsTextEditable  False      ValidateOnTextInput  False      AutoComplete  False      IncrementalFiltering  True      FilterCondition  Like      ImmediatePopup  True   gt    Needsless to say  you will need to point xamlExtensions at the namespace that contains the XAML extension class  which is defined below    xmlns xamlExtensions  clr-namespace XamlExtensions    And we have to point myEnum at the namespace that contains the enum   xmlns myEnum  clr-namespace MyNamespace    Then  the enum   namespace MyNamespace       public enum EnumFilter                Description  Free as a bird            Free   0            Description  I m Somewhat Busy            SomewhatBusy   1            Description  I m Really Busy            ReallyBusy   2           The problem in with the XAML is that we can t use SelectedItemValue  as this throws an error as the setter is unaccessable  bit of an oversight on your part  DevExpress   So we have to modify our ViewModel to obtain the value directly from the object   private EnumFilter  filterSelected   EnumFilter All  public object FilterSelected       get               return  EnumFilter  filterSelected            set               var x    XamlExtensionEnumDropdown EnumerationMember value          if  x    null                         filterSelected    EnumFilter x Value                    OnPropertyChanged  FilterSelected              For completeness  here is the XAML extension from the original answer  slightly renamed    namespace XamlExtensions            lt summary gt              Intent  XAML markup extension to add support for enums into any dropdown box  see http   bit ly 1g70oJy  We can name the items in the             dropdown box by using the  Description  attribute on the enum values           lt  summary gt      public class XamlExtensionEnumDropdown   MarkupExtension               private Type  enumType            public XamlExtensionEnumDropdown Type enumType                        if  enumType    null                                throw new ArgumentNullException  enumType                               EnumType   enumType                     public Type EnumType                       get   return  enumType                private set                               if   enumType    value                                        return                                     var enumType   Nullable GetUnderlyingType value     value                   if  enumType IsEnum    false                                        throw new ArgumentException  Type must be an Enum                                         enumType   value                                   public override object ProvideValue IServiceProvider serviceProvider                        var enumValues   Enum GetValues EnumType                return                   from object enumValue in enumValues                 select new EnumerationMember                                                     Value   enumValue                             Description   GetDescription enumValue                            ToArray                       private string GetDescription object enumValue                        var descriptionAttribute   EnumType                  GetField enumValue ToString                     GetCustomAttributes typeof  DescriptionAttribute   false                   FirstOrDefault   as DescriptionAttribute                return descriptionAttribute    null                   descriptionAttribute Description                   enumValue ToString                        region Nested type  EnumerationMember         public class EnumerationMember                       public string Description   get  set                public object Value   get  set                       endregion           Disclaimer  I have no affiliation with DevExpress  Telerik is also a great library

User · Answer

Try using    lt ComboBox ItemsSource   Binding Source  StaticResource ExampleEnumValues        SelectedValue   Binding Path ExampleProperty     gt

User · Answer

If you are using a MVVM  based on  rudigrobler answer you can do the following   Add the following property to the ViewModel class  public Array ExampleEnumValues   gt  Enum GetValues typeof ExampleEnum      Then in the XAML do the following    lt ComboBox ItemsSource   Binding ExampleEnumValues         gt

User · Answer

Here is a generic solution using a helper method  This can also handle an enum of any underlying type  byte  sbyte  uint  long  etc    Helper Method   static IEnumerable lt object gt  GetEnum lt T gt          var type      typeof T       var names     Enum GetNames type       var values    Enum GetValues type       var pairs             Enumerable Range 0  names Length           Select i   gt  new                   Name      names GetValue i                  Value     values GetValue i              OrderBy pair   gt  pair Name       return pairs     method   View Model   public IEnumerable lt object gt  EnumSearchTypes       get           return GetEnum lt SearchTypes gt              property   ComboBox    lt ComboBox     SelectedValue          Binding SearchType       ItemsSource            Binding EnumSearchTypes       DisplayMemberPath     Name      SelectedValuePath     Value    gt

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Code     public enum RULE                Description   quot                        quot             any           Description   quot                            quot             anyThree           Description   quot                           quot             nearAny           Description   quot                               quot             nearThree            class ExtendRULE               public static object Values                       get                               List lt object gt  list   new List lt object gt                     foreach  RULE rule in Enum GetValues  typeof  RULE                                             string desc   rule GetType   GetMember  rule ToString     0  GetCustomAttribute lt DescriptionAttribute gt    Description                      list Add  new   value   rule  desc   desc                                        return list                                 XAML  lt StackPanel gt      lt ListBox ItemsSource   quot  Binding Source  x Static model ExtendRULE Values   quot  DisplayMemberPath  quot desc quot  SelectedValuePath  quot value quot  SelectedValue  quot  Binding SelectedRule  quot   gt      lt ComboBox ItemsSource  quot  Binding Source  x Static model ExtendRULE Values   quot  DisplayMemberPath  quot desc quot  SelectedValuePath  quot value quot  SelectedValue  quot  Binding SelectedRule  quot   gt                           lt  StackPanel gt

User · Answer

In the viewmodel you can have   public MyEnumType SelectedMyEnumType        get   return  selectedMyEnumType        set                 selectedMyEnumType   value              OnPropertyChanged  SelectedMyEnumType                 public IEnumerable lt MyEnumType gt  MyEnumTypeValues       get               return Enum GetValues typeof MyEnumType                Cast lt MyEnumType gt               In XAML the ItemSource binds to MyEnumTypeValues and SelectedItem binds to  SelectedMyEnumType    lt ComboBox SelectedItem   Binding SelectedMyEnumType   ItemsSource   Binding MyEnumTypeValues   gt  lt  ComboBox gt

User · Answer

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

[.net] Databinding an enum property to a ComboBox in WPF

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