c# - Accessing container properties from child list -

i have container class called paymentplan, holds basic payment summary info. holds list of expectedpayments. basic oop type question, brain appears have gone sleep - have property in expectedpayment class needs interrogate property on paymentplan class determine result.

i'm storing reference paymentplan property on expectedpayment class, however, has public getter, , following ddd, feel bit of code smell. there better way achieve want?

i've removed necessary bits example:

public class paymentplan {     private readonly list<expectedpayment> _payments;      public paymentplan(list<expectedpayment> payments)     {         ... other stuff          //todo: fix smell         _payments = payments;         _payments.foreach(p => p.plan = this);     }      ... other properties } 

and expectedpayment class:

public class expectedpayment {     public expectedpayment(... args removed example)     {     }      //todo: attempting avoid public setter have no control..     public paymentplan plan { get; set; }      public paymentstate paymentstate     {                 {             if (plan.somepropertyonplan == "somevalue")             {                 return paymentstate.somestate;             }             else              {                 ... other logic determine payment state of expected payment.             }         }     }      ... other properties  } 

any appreciated! - know techniques if possible know there multiple ways achieve i'm after.

thanks, alex

as if expectedpayment shouldn't exist if hasn't paymentplan, must force expectedpayment() constructor provide paymentplan caller , add "friendly" method adding new expectedplan on paymentplan .

public class expectedpayment {     public expectedpayment(paymentplan plan, ..... other args)     {         plan = plan ;          plan.addexpectedplan(this) ;          ......     }      ...... 

....

public class paymentplan  {     .........      internal void addexpectedplan(expectedplan expectedplan)      {          ...........         _payments.add(expectedplan) ;      }  }