16. Iterator mode (Iterator pattern)

usingSystem;namespaceconsoleapplication9{classProgram {/// <summary>        ///The iterator pattern provides a way to sequentially access individual elements in an aggregate object (understood as a collection object) .///Without exposing the object's internal representation, so that it does not expose the internal structure of the collection,///It also allows external code to transparently access the data inside the collection. /// </summary>        /// <param name= "args" ></param>        Static voidMain (string[] args)             {Iterator Iterator; Ilistcollection List=Newconcretelist (); Iterator=list.             Getiterator ();  while(iterator. MoveNext ()) {inti = (int) iterator.                 GetCurrent ();                 Console.WriteLine (i.ToString ()); Iterator.             Next ();        } console.read (); }        //Abstract Aggregation Classes         Public Interfaceilistcollection {Iterator getiterator (); }        //iterator abstract class         Public InterfaceIterator {//whether the next object exists            BOOLMoveNext (); //get Subscript ObjectObject GetCurrent (); //Subscript plus 1            voidNext (); //under SD 0            voidReset (); }        //Specific aggregation classes         Public classconcretelist:ilistcollection {int[] collection;  PublicConcretelist () {collection=New int[] {2,4,6,8 }; }             PublicIterator Getiterator () {return NewConcreteiterator ( This); }             Public intLength {Get{returncollection. Length; }            }             Public intGetElement (intindex) {                returnCollection[index]; }        }        //Specific iterator Classes         Public classConcreteiterator:iterator {//iterators need to refer to a collection object for traversal operations.            Privateconcretelist _list; Private int_index;  Publicconcreteiterator (concretelist list) {_list=list; _index=0; }             Public BOOLMoveNext () {if(_index <_list. Length) {return true; }                return false; }             PublicObject GetCurrent () {return_list.            GetElement (_index); }             Public voidReset () {_index=0; }             Public voidNext () {if(_index <_list. Length) {_index++; }            }        }    }}

16. Iterator mode (Iterator pattern)