If I have a class with read-only properties that I only want to be created at constructor time e.g.:-


vb.net Code:
  1. Imports System.Runtime.Serialization

  2.  

  3. ''' <summary>

  4. ''' An event to indicate that an FX rate was priced between two currencies

  5. ''' </summary>

  6. <DataContract()>

  7. Public Class FXRatePricedEvent

  8.     Inherits AggregateIdentity.CurrencyExchangeAggregateIdentity

  9.     Implements IEvent(Of IAggregateIdentity)

  10.  

  11.     <DataMember(Name:="Rate")>

  12.     ReadOnly m_rate As Decimal

  13.     <DataMember(Name:="PriceDate")>

  14.     ReadOnly m_pricedate As Date

  15.     <DataMember(Name:="IsDerived")>

  16.     ReadOnly m_derived As Boolean

  17.  

  18.  
  19.     ''' <summary>

  20.     ''' The conversion rate between source and target currencies

  21.     ''' </summary>

  22.     ReadOnly Property Rate As Decimal

  23.         Get

  24.             Return m_rate

  25.         End Get

  26.     End Property

  27.  

  28.     ''' <summary>

  29.     ''' The date/time the FX rate was priced

  30.     ''' </summary>

  31.     ReadOnly Property PriceDate As Date

  32.         Get

  33.             Return m_pricedate

  34.         End Get

  35.     End Property

  36.  

  37.     ''' <summary>

  38.     ''' Is this rate derived from triangulation or reversal of a priced rate

  39.     ''' </summary>

  40.     ''' <remarks>

  41.     ''' For example a derived GBPJPY can exist s if a priced GBPUSD and USDJPY exist

  42.     ''' </remarks>

  43.     ReadOnly Property IsDerived As Boolean

  44.         Get

  45.             Return m_derived

  46.         End Get

  47.     End Property

  48.  

  49.     Public Sub New(ByVal currencyFrom As AggregateIdentity.CurrencyAggregateIdentity.ISO_3Digit_Currency,

  50.                    ByVal currencyTo As AggregateIdentity.CurrencyAggregateIdentity.ISO_3Digit_Currency,

  51.                    ByVal fxRate As Decimal,

  52.                    ByVal rateDate As Date,

  53.                    ByVal derived As Boolean)

  54.         ' Set the FX rate aggregate identifier

  55.         MyBase.New(currencyFrom, currencyTo)

  56.         ' and set the other properties

  57.         m_rate = fxRate

  58.         m_pricedate = rateDate

  59.         m_derived = derived

  60.     End Sub

  61.  

  62. End Class

Then System.Runtime.Serialization can serialise this to/from XML with no problem. However I want to do something similar but to a key-value pair dictionary....my attempts so to do hit a brick wall unless the class has a constructor with no parameters.

Any ideas how I (or they) get around this?