data binding - Bind a property to another property in C# -

i have class named grid, composed of 2 other classes circle , line.

public class grid {     public circle circle {get; set;}     public line line {get; set;} } 

i want geometry of line stay connected geometry of circle. means when drag or move circle. want line notified somehow , updated geometry according new location of circle.

of course can create new grid updated geometries of circle , line, not want create new grid. want somehow bind end-points of line example circle's center.

what technologies in c# allows me this? delegates? inotifypropertychanged?

public class circle : inotifypropertychanged {     private int radius;            public int radius      {         { return radius; }         set          {             radius = value;             raisepropertychanged("radius");         }     }      public event propertychangedeventhandler propertychanged;      private void raisepropertychanged(string propertyname)     {         var propchange = propertychanged;         if (propchange == null) return;         propchange(this, new propertychangedeventargs(propertyname));     } } 

then in grid.cs

public class grid {     private circle circle;     public circle circle      {        { return circle; }        set         {            circle = value;            if (circle != null)                circle.propertychanged += onpropertychanged;        }     }      private void onpropertychanged(object sender, propertychangedeventargs e)     {         if (e.propertyname == "radius")             // line     } }