Is there a cleaner way ?

With this workaround, if the user types "12.3" it will display "0012.30" when in fact, we need to display "12.30". 

In my case, I use the XamNumericEditor to display currency and percentages, so the decimal numbers are really important (12.30$  versus 12.3$ or 0012.30$)

Any other solution ?

Thank you,

Not really, sorry. I think an image's worth a thousand words, so I've attached what is happening and what I expect.

While the control has focus, it is OK to display prompt chars and it does not matter if "12.3" is typed in without the 0 at the end. However, when the control loses focus, I want it to automatically format to "12.30" (a kind of ValueToDisplayTextConverter). However, no DisplayMode allows to do that.

Here's what I do to edit an amount in CAD$ :  

<ig:XamNumericEditor Padding="0,0,15,0" Mask="{}{double:6.2}" ValueType="my:Double" PromptChar=" " ValidationMode="Always" Value="{Binding MONTANT, Mode=TwoWay}" Minimum="0" DisplayMode="{Binding MONTANT, Converter={StaticResource neDisplayModeConverter}}" />

<TextBlock Grid.Row="0" Grid.Column="2" Text="$" Margin="0,0,5,0" HorizontalAlignment="Right" VerticalAlignment="Center" />

And here's the converter that allows to display an empty box instead of "   .   " when the value is null : 
public class XamNumericEditorDisplayModeConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
if (value == null || !(value is double))
  return Infragistics.Controls.Editors.MaskMode.Raw;
else
  return Infragistics.Controls.Editors.MaskMode.IncludeLiterals;
}
.
.
.
}

Is there any way to use a converter or something else to format the text that represents the value when the control is NOT in edit mode (when it does not have focus) ?

Thanks for your help :)

Remove the PromptChar="0"

You no longer see the 0s but you do see lines for digits.

Or set the PromptChar=" "  [space], then all you see is the decimal point.

Take a look, does that help?  But as far as I can tell, there is no auto filling for the currency.

Thanks,

Richard