mvvm轻调用RaisePropertyChanged不会触发Property getter（Windows Phone 8.1）

Question

in my application I have a textbox that user type a number on it. I want to this Latin number to Persian one as user type it. after calling RaisePropertychanged the getter of MobileNumber not called so App Ui doesn't update. what is the problem with my code?

here is my code

View.xaml

<Page
x:Class="CustomName.RegistrationPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:ShahrMobileBank.Views.Masters.Registration"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:behaviors="using:Template10.Behaviors"
xmlns:interactivity="using:Microsoft.Xaml.Interactivity"
xmlns:core="using:Microsoft.Xaml.Interactions.Core"
xmlns:converter="using:ShahrMobileBank.Converter"
mc:Ignorable="d"
DataContext="{Binding Path=RegistrationPage, Source={StaticResource ViewModelLocator}}">

    <StackPanel Background="{StaticResource RegistrationPageBackgroundColor}" x:Name="LayoutRoot">
        <StackPanel.Resources>
            <converter:RegistrationConverter x:Key="RegistrationConverter"/>
        </StackPanel.Resources>

        <TextBox Style="{StaticResource GenericTextBoxBeforeLogin}"  x:Uid="PhoneNumber" InputScope="Number" Text="{Binding Path=MobileNumber,  Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" MaxLength="{StaticResource MobileNumberMaxLength}"/>
</StackPanel>
</Page>

ViewModel.cs

public class RegistrationPageViewModel : ViewModelBase
{
    private string _mobileNumber;

    public String MobileNumber
    {
        get
        {
            return _mobileNumber;
        }
        set
        {
            _mobileNumber = LangUtil.ConvertEnNumberToFaNumber(value); // this converts the number from Latin to Persian
            RaisePropertyChanged(() => MobileNumber);
        }
    }
}

Answer 1

Try changing the RaisePropertyChanged line to RaisePropertyChanged("MobileNumber");

If you use the MVVM-Light Code snippets (if installed, you can start typing mvvm, and intellisense will pop up), you can look at mvvmpinpc which is one of the PropertyChanged code snippets. You can Tab through the different template fields to set it up to what you want, as well as possibly shed any light on little tips and tricks to make your coding life easier.