C#索引器（Indexers）---逐步解析与理解（二）
继续前面一篇文章
在Employee类中为get和set存取器创建索引。完整的Employee类如下，这里，我们通过索引位置创建了一个索引，这样我们就能通过整型索引位置存取元素。在set存取器中，参数“value”是隐式保存赋值的。
1 using System; 2 namespace IndexersDemo 3 { 4 public class Employee 5 { 6 //Declare the properties 7 public int ID { get; set; } 8 public string Name { get; set; } 9 public string Job { get; set; } 10 public double Salary { get; set; } 11 public string Location { get; set; } 12 public string Department { get; set; } 13 public string Gender { get; set; } 14 15 //Initialize the properties through constructor 16 public Employee(int ID, string Name, string Job, int Salary, string Location, 17 string Department, string Gender) 18 { 19 this.ID = ID; 20 this.Name = Name; 21 this.Job = Job; 22 this.Salary = Salary; 23 this.Location = Location; 24 this.Department = Department; 25 this.Gender = Gender; 26 } 27 28 public object this [int index] 29 { 30 //The get accessor is used for returning a value 31 get 32 { 33 if (index == 0) 34 return ID; 35 else if (index == 1) 36 return Name; 37 else if (index == 2) 38 return Job; 39 else if (index == 3) 40 return Salary; 41 else if (index == 4) 42 return Location; 43 else if (index == 5) 44 return Department; 45 else if (index == 6) 46 return Gender; 47 else 48 return null; 49 } 50 51 // The set accessor is used to assigning a value 52 set 53 { 54 if (index == 0) 55 ID = Convert.ToInt32(value); 56 else if (index == 1) 57 Name = value.ToString(); 58 else if (index == 2) 59 Job = value.ToString(); 60 else if (index == 3) 61 Salary = Convert.ToDouble(value); 62 else if (index == 4) 63 Location = value.ToString(); 64 else if (index == 5) 65 Department = value.ToString(); 66 else if (index == 6) 67 Gender = value.ToString(); 68 } 69 } 70 } 71 }
现在，像数组一样存取这些数值元素，同时，也可以像数组一样修改这些数值元素。
1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Text; 5 6 namespace IndexersDemo 7 { 8 public class Employee 9 { 10 //Declare the properties 11 public int ID { get; set; } 12 public string Name { get; set; } 13 public string Job { get; set; } 14 public double Salary { get; set; } 15 public string Location { get; set; } 16 public string Department { get; set; } 17 public string Gender { get; set; } 18 19 //Initialize the properties through constructor 20 public Employee(int ID, string Name, string Job, int Salary, string Location, 21 string Department, string Gender) 22 { 23 this.ID = ID; 24 this.Name = Name; 25 this.Job = Job; 26 this.Salary = Salary; 27 this.Location = Location; 28 this.Department = Department; 29 this.Gender = Gender; 30 } 31 32 public object this[int index] 33 { 34 get 35 { 36 if (index == 0) 37 return ID; 38 else if (index == 1) 39 return Name; 40 else if (index == 2) 41 return Job; 42 else if (index == 3) 43 return Salary; 44 else if (index == 4) 45 return Location; 46 else if (index == 5) 47 return Department; 48 else if (index == 6) 49 return Gender; 50 else 51 return null; 52 } 53 set 54 { 55 if (index == 0) 56 ID = Convert.ToInt32(value); 57 else if (index == 1) 58 Name = value.ToString(); 59 else if (index == 2) 60 Job = value.ToString(); 61 else if (index == 3) 62 Salary = Convert.ToDouble(value); 63 else if (index == 4) 64 Location = value.ToString(); 65 else if (index == 5) 66 Department = value.ToString(); 67 else if (index == 6) 68 Gender = value.ToString(); 69 } 70 } 71 } 72 73 class Program 74 { 75 static void Main(string[] args) 76 { 77 //Creating the Employee instance 78 Employee emp = new Employee(101, "Pranaya", "SSE", 10000, "Mumbai", "IT", "Male"); 79 80 //Accessing Employee Properties using Indexers i.e. using Index positions 81 Console.WriteLine("EID = " + emp[0]); 82 Console.WriteLine("Name = " + emp[1]); 83 Console.WriteLine("Job = " + emp[2]); 84 Console.WriteLine("Salary = " + emp[3]); 85 Console.WriteLine("Location = " + emp[4]); 86 Console.WriteLine("Department = " + emp[5]); 87 Console.WriteLine("Gender = " + emp[6]); 88 89 emp[1] = "Kumar"; 90 emp[3] = 65000; 91 emp[5] = "BBSR"; 92 93 Console.WriteLine("=======Afrer Modification========="); 94 Console.WriteLine("EID = " + emp[0]); 95 Console.WriteLine("Name = " + emp[1]); 96 Console.WriteLine("Job = " + emp[2]); 97 Console.WriteLine("Salary = " + emp[3]); 98 Console.WriteLine("Location = " + emp[4]); 99 Console.WriteLine("Department = " + emp[5]); 100 Console.WriteLine("Gender = " + emp[6]); 101 Console.ReadLine(); 102 } 103 } 104 }
运行程序，输出结果如下：
