要使用foreach的遍历的类首先要满足的条件
1、类要实现公共方法 public IEnumerator GetEnumerator(){}，还可以继承IEnumerable接口来实现这个方法
2、类实现了 public IEnumerator GetEnumerator(){}中，要返回一个对象用于遍历的，当然这个对象必须继承IEnumerator 接口
1 class Program 2 { 3 static void Main(string[] args) 4 { 5 Person p = new Person(); 6 p[0] = "小明"; 7 p[1] = "晓虹"; 8 p[2] = "小芳"; 9 p[3] = "小龙"; 10 for (int i = 0; i < p.Count; i++) 11 { 12 Console.WriteLine(p[i]); 13 } 14 15 Console.WriteLine("=========================================="); 17 foreach (var name in p) 18 { 19 Console.WriteLine(name); 20 } 21 Console.ReadKey(); 22 } 23 } 24 25 internal class Person:IEnumerable 26 { 27 private List<string> listStudent =new List<string>(); 28 public int Count { 29 get { return listStudent.Count; } 30 } 31 32 public string this[int index] 33 { 34 get { return listStudent[index]; } 35 set 36 { 37 if (index>=Count) 38 { 39 listStudent.Add(value); 40 } 41 else 42 { 43 listStudent[index] = value; 44 } 45 } 46 } 47 48 49 50 public IEnumerator GetEnumerator() 51 { 52 return new PersonIEnumerator(listStudent); 53 } 54 } 55 56 class PersonIEnumerator:IEnumerator 57 { 58 public PersonIEnumerator(List<string> _listName) 59 { 60 listName = _listName; 61 } 62 63 private List<string> listName; 64 private int index = -1; 65 66 public object Current 67 { 68 get {return listName[index]; } 69 } 70 71 public bool MoveNext() 72 { 73 index++; 74 if (index>=listName.Count) 75 { 76 return false; 77 } 78 else 79 { 80 return true; 81 } 82 } 83 84 public void Reset() 85 { 86 index = -1; 87 } 88 } |
