How can I binding an enum with IValueConverter? - wpf

Question

Here is the enum:
public enum BarcodeType
{ AZTEC, CODABAR, CODE128, CODE93, CODE39, DATA_MATRIX, EAN13, EAN8, ITF, MAXICODE, PDF417, QRCODE, RSS14, RSSEXPANDED, UPCA, UPCE, UPC_EAN_EXTENSION }
And I bind the enum to the ComboBox like this:
<Page x:Class="KongGamLung.ToolProperty.BarCodeProperty"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:KongGamLung.ToolProperty"
xmlns:System="clr-namespace:System;assembly=mscorlib"
xmlns:Model="clr-namespace:KongGamLung.Models"
mc:Ignorable="d"
d:DesignHeight="450" d:DesignWidth="800"
Title="BarCodeProperty">
<Page.Resources>
<ObjectDataProvider x:Key="dataFromEnum" MethodName="GetValues"
ObjectType="{x:Type System:Enum}">
<ObjectDataProvider.MethodParameters>
<x:Type TypeName="Model:BarcodeModel+BarcodeType"/>
</ObjectDataProvider.MethodParameters>
</ObjectDataProvider>
<local:BarcodeTypeConverter x:Key="BarcodeTypeConverter"/>
</Page.Resources>
<ComboBox x:Name="BarcodeTypeCB" ItemsSource="{Binding Source={StaticResource dataFromEnum},Converter={StaticResource BarcodeTypeConverter}}">
</ComboBox>
</Page>
And here is code-behind:
public class BarcodeTypeConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
return Enum.GetName(value.GetType(), value).ToString().Replace("_", " ");
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}
The code works well while without the code of the IValueConverter.
I use the IValueConverter for I want to replace the character of '_' in enum to ' ' to make it looks better.
I code the IValueConverter as what https://social.msdn.microsoft.com/Forums/vstudio/en-US/43db6b07-f886-4214-8076-5a5ec2360616/valueconverter-that-converts-an-enum-value-to-its-corresponding-string-value?forum=wpf said. But finally, it throws a System.ArgumentException error.
How can I solve it? Would you please help me? Thank you.

Answer 1

Don't use a converter on ItemsSource, it's changes the type of data that you're binding to. If you need to change the appearance of the enum then specify an ItemTemplate instead and use your converter there:
<ComboBox ItemsSource="{Binding Source={StaticResource dataFromEnum}}">
<ComboBox.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding Path=., Converter={StaticResource BarcodeTypeConverter}}" />
</DataTemplate>
</ComboBox.ItemTemplate>
</ComboBox>
Personally I'd bind to an intermediate view model class instead that contains both the enum and the text, that makes it much easier down the track to support things like localization (i.e. multiple languages at runtime).