It's a known issue, the binding doesn't use the system current culture to format values. You can create you own value converter to implement it.
public class FrDateValueConverter
: IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
if (value is DateTime)
{
var date = (DateTime) value;
return date.ToString(new CultureInfo("fr-Fr"));
}
return value;
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}
now you should add the converter to the resources
<FrDateValueConverter x:Key="MyConv" />
finally you should specify Converter parameter of the binding
<TextBlock Grid.Row="1" Margin="0,2,0,0" Text="{Binding DateModifElement, Converter={StaticResource MyConv}}" Foreground="{StaticResource C01}" FontSize="16"/>