How to access to the parent object in c

Question

I have a  meter  class  One property of  meter  is another class called  production   I need to access to a property of meter class  power rating  from production class by reference  The powerRating is not known at the instantiation of Meter   How can I do that     Thanks in advance  public class Meter      private int  powerRating   0      private Production  production      public Meter               production   new Production

User · Accepted Answer

Store a reference to the meter instance as a member in Production:

public class Production {
  //The other members, properties etc...
  private Meter m;

  Production(Meter m) {
    this.m = m;
  }
}

And then in the Meter-class:

public class Meter
{
   private int _powerRating = 0; 
   private Production _production;

   public Meter()
   {
      _production = new Production(this);
   }
}

Also note that you need to implement an accessor method/property so that the Production class can actually access the powerRating member of the Meter class.

User · Answer

Why not change the constructor on Production to let you pass in a reference at construction time   public class Meter      private int  powerRating   0      private Production  production      public Meter               production   new Production this            In the Production constructor you can assign this to a private field or a property  Then Production will always have access to is parent

User · Answer

I would give the parent an ID  and store the parentID in the child object  so that you can pull information about the parent as needed without creating a parent-owns-child child-owns-parent loop

User · Answer

You would need to add a property to your Production class and set it to point back at its parent  this doesn t exist by default

User · Answer

I wouldn t reference the parent directly in the child objects  In my opinion the childs shouldn t know anything about the parents  This will limits the flexibility    I would solve this with events handlers   public class Meter       private int  powerRating   0      private Production  production       public Meter                  production   new Production             production OnRequestPowerRating    new Func lt int gt  delegate   return  powerRating               production DoSomething             public class Production       protected int RequestPowerRating                 if  OnRequestPowerRating    null              throw new Exception  OnRequestPowerRating handler is not assigned             return OnRequestPowerRating               public void DoSomething                 int powerRating   RequestPowerRating            Debug WriteLine  The parents powerrating is      powerRating               public Func lt int gt  OnRequestPowerRating      In this case I solved it with the Func lt   generic  but can be done with  normal  functions  This why the child Production  is totally independent from it s parent Meter      But  If there are too many events handlers or you just want to pass a parent object  i would solve it with an interface   public interface IMeter       int PowerRating   get       public class Meter   IMeter       private int  powerRating   0      private Production  production       public Meter                  production   new Production this            production DoSomething               public int PowerRating   get   return  powerRating         public class Production       private IMeter  meter       public Production IMeter meter                 meter   meter             public void DoSomething                 Debug WriteLine  The parents powerrating is       meter PowerRating             This looks pretty much the same as the solution mentions  but the interface could be defined in another assembly and can be implemented by more than 1 class     Regards  Jeroen van Langen

User · Answer

You could maybe add a method to your Production object called  SetPowerRating int   which sets a property in Production  and call this in your Meter object before using the property in the Production object

User · Answer

something like this     public int PowerRating              get   return base PowerRating       if power inherits from meter

[c#] How to access to the parent object in c#

Examples related to c#

Examples related to oop

Examples related to parent