深入IComparable與IComparer的排序執行個體詳解

如下所示： 複製代碼 代碼如下: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("張三", 2800);
Employees[1] = new Employee("李四", 1800);
Employees[2] = new Employee("王五", 5800);
Employees[3] = new Employee("馬六", 12800);
Employees[4] = new Employee("錢七", 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;
}
//顯示介面實現
int IComparable.CompareTo(object obj)
{
if (!(obj is Employee))
{
throw new ArgumentException("不是Employee類");
}
return _Name.CompareTo(((Employee)obj)._Name);
}
//提供一個公用的強型別重載版本
public int CompareTo(Employee Em)
{
return _Name.CompareTo(Em._Name);
}
//當第一次執行個體化Employee的時候,_SalaryCom為空白,當使用SalaryCom時,就會建立一個SalaryCompare對象,第2次，3次的時候,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;
}
}
//嵌套類(這個類是針對薪水進行排序的類)
private class SalaryCompare:IComparer
{
//使用指定的IComparer對Array中的元素進行排序
int IComparer.Compare(object obj1,object obj2)
{
if (!(obj1 is Employee) || !(obj2 is Employee))
{
throw new ArgumentException("不是Employee類");
}
return ((Employee)obj1)._Salary.CompareTo(((Employee)obj2)._Salary);
}
}
public override string ToString()
{
return _Name +" "+ _Salary.ToString();
}
}
}