WPF bind enum to combobox

Question

In my WPF UserControl I need to bind an Enum on a ComboBox. This enum is declared locally:

public partial class ViewerDataConfiguration : UserControl { private ViewerDataConfigurationViewModel PageViewModel; public Visibility IsParametriSelected { get; set; } public IEnumerable<eDatoAlarmMode> EnumAlarmModes { get { return Enum.GetValues(typeof(eDatoAlarmMode)).Cast<eDatoAlarmMode>(); } }

On the main Grid, where there is a collection bound, I defined a ComboBox as follows:

<TextBox Grid.Column="16" Text="{Binding ConfigObject.Edit.Source}" Style="{StaticResource txtDataStyle2}" Width="30" Visibility="{Binding ConfigObject.Edit, Converter={StaticResource ListaValoriVisibilityConverter}}" HorizontalAlignment="Stretch" TextChanged="Data_TextChanged" /> <Label Grid.Column="17" Content="AlarmMode" Style="{StaticResource labelStyle2}" /> <ComboBox Grid.Column="18" Width="30" ItemsSource="{Binding Path=EnumAlarmModes, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=local:ViewerDataConfiguration}}" DisplayMemberPath="Value" SelectedValuePath="Value" Style="{StaticResource comboUsersStyle}" />

Basically seems that my IEnumerable is not bound correctly. I see the elements but they're blank. Any hint?

Martin Zikmund · Accepted Answer · 2018-02-09 09:45:01Z

You are using DisplayMemberPath and SelectedValuePath attributes, but your collection item type is just a simple string, and want to use this entire instance directly, so you should remove these attributes and it should work as expected.

You also need to change the field to a property as data binding works only on properties, not class fields (although x:Bind in UWP no longer has this limitation):

 public IEnumerable<AlarmMode> EnumAlarmModes { get { return Enum.GetValues(typeof(AlarmMode)).Cast<AlarmMode>(); } }

If you want to display enum values instead of names, create a value converter:

public class EnumValueConverter : IValueConverter { public object Convert(object value, Type targetType, object parameter, CultureInfo culture) { return (int)value; } public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture) { throw new NotImplementedException(); } }

And then use it in the ItemTemplate:

<ComboBox Grid.Column="18" Width="100" ItemsSource="{Binding Path=EnumAlarmModes}"> <ComboBox.Resources> <local:EnumValueConverter x:Key="EnumValueConverter" /> </ComboBox.Resources> <ComboBox.ItemTemplate> <DataTemplate> <TextBlock Text="{Binding Converter={StaticResource EnumValueConverter}}" /> </DataTemplate> </ComboBox.ItemTemplate> </ComboBox>

For this to work you also have to add a xmlns:local declaration to your Window:

xmlns:local="clr-namespace:NamespaceOfConverter"

I slightly modified the code, as in effect a IEnumerable of string is not usefu as I need to bind name and value in the combobox. So the property now is: public IEnumerable<eDatoAlarmMode> EnumAlarmModes { get { return Enum.GetValues(typeof(eDatoAlarmMode)).Cast<eDatoAlarmMode>(); } } And I restored the DisplayMemberPath="Value" SelectedValuePath="Name"
Nope... my enum contains 3 items, I only see 3 empty items binded in the combobox
Remove the DisplayMemberPath and SelectedValuePath attributes, it works well without them.
Also if you want to display enum value instead of name, I have updated my answer with the solution.

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