DecimalPercentageConverter

         < StackPanel  x:Name ="StackPanelPerson"  Grid.Row ="1"  Width ="200" >
             < TextBox  Text =" {Binding Mode=TwoWay, Path=UnitPrice, ValidatesOnExceptions=True, NotifyOnValidationError=True, StringFormat=\{0:F\}} " />
             < TextBox  Height ="23"  Text =" {Binding Mode=TwoWay, Path=UnitPriceRate, ValidatesOnExceptions=True, NotifyOnValidationError=True, Converter={StaticResource DecimalPercentageConverter}, StringFormat=\{0:P\}} "   />
             < TextBox  Text =" {Binding Mode=TwoWay, Path=SuggestPrice, ValidatesOnExceptions=True, NotifyOnValidationError=True, StringFormat=\{0:F\}} " />
             < TextBox  Height ="23"  Text =" {Binding Mode=TwoWay, Path=SuggestPriceRate, ValidatesOnExceptions=True, NotifyOnValidationError=True, Converter={StaticResource DecimalPercentageConverter}, StringFormat=\{0:P\}} "   />
             < sdk:Label  x:Name ="LabelMessage"   />
             < Button  Content ="test"  Click ="Button_Click_1"   />
         </ StackPanel >

     public class DecimalPercentageConverter : IValueConverter

    {
         public  object Convert( object value, Type targetType,  object parameter, System.Globalization.CultureInfo culture)
        {
             return value;
        }

         public  object ConvertBack( object value, Type targetType,  object parameter, System.Globalization.CultureInfo culture)
        {
             if (targetType !=  typeof( decimal) || value ==  null)
                 return value;

             string str = value.ToString();

             if (String.IsNullOrWhiteSpace(str))
                 return 0M;

            str = str.TrimEnd(culture.NumberFormat.PercentSymbol.ToCharArray());

             decimal result = 0M;
             if ( decimal.TryParse(str,  out result))
            {
                result /=  100;
            }
             return result;
        }
    }