Using enum descriptions to string/text binding

In my WP8 application I need to show a couple of radio buttons to let the user select a value out of an enum. I don't want to hardcode either the value or the text (description) showed to the user. I would like my Model/ViewModel drive them for me.

As of now, this is what I have:

//enum defined in model
 public enum Units
    {
        [Description ("Meters/km")]
        Metric,
        [Description ("Feet/Miles")]
        Imperial
    }

Converters defined to handle string and Boolean conversions

```
//Converts ENum to boolean and back
// Convert: uses parameter passed in, returns true if current value of the Enum matches parameter
//ConvertBack: if value is true, sets the value of the ENum to parameter passed in
//
[ValueConversion (typeof (Enum), typeof (Boolean))]
public class EnumToBooleanConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
string parameterString = parameter as string;
if ( parameterString == null )
return DependencyProperty.UnsetValue;

if ( Enum.IsDefined (value.GetType (), value) == false )
return DependencyProperty.UnsetValue;

object parameterValue = Enum.Parse (value.GetType (), parameterString);

return parameterValue.Equals (value);

}

public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
return value.Equals (true) ? Enum.Parse(targetType, parameter as String) : DependencyProperty.UnsetValue;
}
}

//Converts ENum to strings, uses Description for the parameter passed in, or parameter as string
[ValueConversion (typeof (Enum), typeof (String))]
public class EnumToStringConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
string parameterString = parameter as string;

This looks perfectly reasonable. In fact, the only thing I would really change is this:

string parameterString = parameter as string;
if ( parameterString == null )
    return DependencyProperty.UnsetValue;

if ( Enum.IsDefined (value.GetType (), value) == false )
    return DependencyProperty.UnsetValue;

You have this in both Convert methods, and it would be just as clear like this:

string parameterString = parameter as string;
if ( parameterString == null || !Enum.IsDefined (value.GetType (), value) )
    return DependencyProperty.UnsetValue;

Additionally, you could concatenate this:

object parameterValue = Enum.Parse (value.GetType (), parameterString);
return parameterValue.Equals (value);

Like this:

return Enum.Parse (value.GetType(), parameterString).Equals (value);

For your XAML, you do not need to put each property on its own individual line. I typically only break them up when they do not fit on my screen all at once, more like this





Finally, for your UI, you most likely want to label your radio buttons as what they are, and perhaps change your UI a little to accommodate the labels and still look good. I would recommend a ComboBox if you have trouble adjusting the UI to look good. You could then bind the SelectedItem or SelectedIndex to a value in your VM and use a converter to change the value as needed.


Metric (meters)
Imperial (feet)



StackExchange Code Review Q#77333, answer score: 8