数组

排序

Person.cs

public class Person : IComparable<Person>
{
　　public string FirstName { get; set; }
　　public string LastName { get; set; }
　　public override string ToString()
   {
       return String.Format("{0} {1}",FirstName, LastName);
   }
　　public int CompareTo(Person other)
   {
       if (other == null) throw new ArgumentNullException("other");
       int result = this.LastName.CompareTo(other.LastName);
       if (result == 0)
       {
           result = this.FirstName.CompareTo(other.FirstName);
       }
       return result;
   }
}

 

PersonComparer.cs

public enum PersonCompareType
{
　　FirstName,
　　LastName
}
 
public class PersonComparer : IComparer<Person>
{
　　private PersonCompareType compareType;
　　public PersonComparer(PersonCompareType compareType)
　　{
　　　　this.compareType = compareType;
　　}
   public int Compare(Person x, Person y)
　　{
　　　　if (x == null) throw new ArgumentNullException("x");
　　　　if (y == null) throw new ArgumentNullException("y");
　　　　switch (compareType)
　　　　{
　　　　　　case PersonCompareType.FirstName:
　　　　　　　　return x.FirstName.CompareTo(y.FirstName);
　　　　　　case PersonCompareType.LastName:
　　　　　　　　return x.LastName.CompareTo(y.LastName);
　　　　　　default:
　　　　　　　　throw new ArgumentException("unexpected compare type");
        }
    }
}

 

Program.cs

class Program
{
　　static void Main()
　　{
　　　　SortNames();
       Person[] persons = GetPersons();
       SortPersons(persons);
       Console.WriteLine();
       SortUsingPersonComparer(persons);
       Covariance(persons);
   }
 
   static void Covariance(object[] objects)
   {
   }
 
   static void SortUsingPersonComparer(Person[] persons)
   {
       Array.Sort(persons, new PersonComparer(PersonCompareType.FirstName));
       foreach (Person p in persons)
       {
          Console.WriteLine(p);
       }
   }
 
   static Person[] GetPersons()
   {
       return new Person[] {
           new Person { FirstName="Damon", LastName="Hill" },
           new Person { FirstName="Niki", LastName="Lauda" },
           new Person { FirstName="Ayrton", LastName="Senna" },
           new Person { FirstName="Graham", LastName="Hill" }
        };
   }
 
   static void SortPersons(Person[] persons)
   {
       Array.Sort(persons);
       foreach (Person p in persons)
       {
           Console.WriteLine(p);
       }
   }
   static void SortNames()
   {
       string[] names = {
           "Christina Aguilera",
           "Shakira",
           "Beyonce",
           "Gwen Stefani"
        };
        Array.Sort(names);
        foreach (string name in names)
        {
            Console.WriteLine(name);
        }
    }
}