This class is used by formatters to identify objects within a serialized stream in order to track object references. The IDs are 64-bit numbers that are generated when an object is referenced or is referencing another. (An ID with a zero value is a null reference.) The GetId( ) method creates and returns an ID for an object if it does not already have one.

public class ObjectIDGenerator {
// Public Constructors
   public ObjectIDGenerator( );
// Public Instance Methods
   public virtual long GetId(object obj, out bool firstTime);
   public virtual long HasId(object obj, out bool firstTime);
}