IComparable,IComparer排序实例

using System; using System.Collections.Generic; using System.Text; using System.Collections; namespace hgoApp { class Comparer { static void Main() { Employee[] Employees = new Employee[5]; Employees[0] = new Employee("张三", 2800); Employees[1] = new Employee("李四", 1800); Employees[2] = new Employee("王五", 5800); Employees[3] = new Employee("马六", 12800); Employees[4] = new Employee("钱七", 8800); Console.WriteLine("按照姓名排序"); Array.Sort(Employees); foreach (Employee em in Employees) { Console.WriteLine(em); } Console.WriteLine("按照薪水排序"); Array.Sort(Employees, Employee.SalaryCom); foreach (Employee em in Employees) { Console.WriteLine(em); } } } class Employee : IComparable { private string _Name; public string Name { get { return _Name; } } private int _Salary; public int Salary { get { return _Salary; } } public Employee(string Name, int Salary) { _Name = Name; _Salary = Salary; } //显示接口实现 int IComparable.CompareTo(object obj) { if (!(obj is Employee)) { throw new ArgumentException("不是Employee类"); } return _Name.CompareTo(((Employee)obj)._Name); } //提供一个公用的强类型重载版本 public int CompareTo(Employee Em) { return _Name.CompareTo(Em._Name); } //当第一次实例化Employee的时候,_SalaryCom为空,当使用SalaryCom时,就会创建一个SalaryCompare对象,第2次，3次的时候,就可以直接使用_SalaryCom了 private static SalaryCompare _SalaryCom = null; public static IComparer SalaryCom { get { if (_SalaryCom == null) { _SalaryCom = new SalaryCompare(); } return _SalaryCom; } } //嵌套类(这个类是针对薪水进行排序的类) private class SalaryCompare:IComparer { //使用指定的IComparer对Array中的元素进行排序 int IComparer.Compare(object obj1,object obj2) { if (!(obj1 is Employee) || !(obj2 is Employee)) { throw new ArgumentException("不是Employee类"); } return ((Employee)obj1)._Salary.CompareTo(((Employee)obj2)._Salary); } } public override string ToString() { return _Name +" "+ _Salary.ToString(); } } }