索引器允许对对象(例如数组)进行索引。
让我们看看语法-
element-type this[int index] { //获取访问器。 get { //返回由索引指定的值 } //设置的访问器。 set { //设置索引指定的值 } }
以下是显示如何在C#中实现索引器的示例-
using System; namespace Demo { class Program { private string[] namelist = new string[size]; static public int size = 10; public Program() { for (int i = 0; i < size; i++) namelist[i] = "N. A."; } public string this[int index] { get { string tmp; if( index >= 0 && index <= size-1 ) { tmp = namelist[index]; } else { tmp = ""; } return ( tmp ); } set { if( index >= 0 && index <= size-1 ) { namelist[index] = value; } } } static void Main(string[] args) { Program names = new Program(); names[0] = "Tom"; names[1] = "Jacob"; names[2] = "Jack"; names[3] = "Amy"; names[4] = "Katy"; names[5] = "Taylor"; names[6] = "Brad"; names[7] = "Scarlett"; names[8] = "James"; for ( int i = 0; i < Program.size; i++ ) { Console.WriteLine(names[i]); } Console.ReadKey(); } } }
输出结果
Tom Jacob Jack Amy Katy Taylor Brad Scarlett James N. A.