=======================================================

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Data;
using System.Globalization;

namespace ConverterTest
{
    class DoubleConverter: IValueConverter
    {

        public object Convert(object value, Type targetType,
                object parameter, CultureInfo culture)
            {
                try
                {
                    return Double.Parse(value.ToString()) * 2;
                }
                catch (Exception)
                {
                    return "#fail";
                }
            }

            public object ConvertBack(object value, Type targetType,
                object parameter, CultureInfo culture)
            {

                try
                {
                    return Double.Parse(value.ToString()) / 2;
                }
                catch (Exception)
                {
                    return "#fail";
                }
            }
        }

}