實現Foreach遍歷

實現Foreach遍歷的集合類，需要實現IEnumerable接口，泛型集合則需要實現IEnumerable<T>接口

using System;using System.Collections;using System.Collections.Generic;using System.Linq;using System.Text;namespace Foreach{    public  class ListForeach<T> :IEnumerable<T>  where T :class ,new()    {        PRivate  T[] array;        private int index = 0;        public ListForeach(int  capcity)        {            array = new T[capcity];        }        public int Count        {            get            {                return index;            }        }        public void Add(T value)         {                       if (index >= array.Length)              {                 T[] newArr = new T[array.Length * 2];                //將原來的數組中的數據拷貝到新數組中.                Array.Copy(array, newArr, array.Length);                //然后將舊數組的變量指向新數組                array = newArr;            }            array[index++] = value;        }        public IEnumerator<T> GetEnumerator()        {            return new TEnumeratro<T>(array, index);                    }        IEnumerator IEnumerable.GetEnumerator()        {            return GetEnumerator();        }    }    public class  TEnumeratro<T> : IEnumerator<T>    {         private  T [] arr ;         private int count;         private int position = -1;         public TEnumeratro(T [] array, int count)        {            this.arr = array;            this.count = count;        }        public T Current        {            get {                return arr[position];            }        }        public void Dispose()        {            arr = null;        }        object IEnumerator.Current        {            get {                return  this.Current;            }        }        public bool MoveNext()        {            position++;            if (position < this.count)                return true;            else                return false;        }        public void Reset()        {            this.position = -1;        }    }}

客戶端代碼

using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace Foreach{    public class Student    {        public int Age {get;set; }        public string  Name { get; set; }            }    class Program    {        static void Main(string[] args)        {            ListForeach<Student> list = new ListForeach<Student>(10);            list.Add(new Student() {Age=111,Name="123" });            list.Add(new Student() { Age = 222, Name = "222" });            list.Add(new Student() { Age = 333, Name = "111" });            list.Add(new Student() { Age = 444, Name = "23222" });            list.Add(new Student() { Age = 22552, Name = "32" });            list.Add(new Student() { Age = 222, Name = "1111334" });            foreach (var s in list)            {                Console.WriteLine(s.Name+":"+ s.Age);            }            ListForeach<Student> list1 = new ListForeach<Student>(10) {             new Student(){ Age=666,Name="yjq"},            new Student(){ Age=88,Name="dddd"},            new Student(){ Age=999,Name="ddd"},            new Student(){ Age=000,Name="==="},            };            foreach (var s in list1)            {                Console.WriteLine(s.Name + ":" + s.Age);            }            Console.Write(list.Count);            Console.Read();                   }    }}