Sorting Generic List in C#

You can sort a generic List in C# using different methods. Here I cover only two options which I found them most handy. The third option is to put the method into a class that implements the IComparer interface.





using System;
using System.Collections.Generic;

public class SortingList
{
      /// <summary>
      /// SortingList: This snippet code demonstrates the delegate method of sorting lists
      /// I define an Item type having some fields and sort based on a preferred field
      /// To do so I need to implement a method would be called during the sort action for each pair.
      ///
      /// NOTE: You could also create a class implementing IComparer and use the class to pass to the Sort method.
      ///
      /// Asghar Panahy
      /// 07-12-2007
      /// </summary>
      public static void Main()
      {
            List<Item> list = new List<Item>();

            // Adding some dummy items
        list.Add(new Item("6", " Asghar 1"));
        list.Add(new Item("5", " Asghar 2"));
        list.Add(new Item("3", " Asghar 3"));
        list.Add(new Item("4", " Asghar 4"));
        list.Add(new Item("2", " Asghar 5"));
        list.Add(new Item("1", " Asghar 6"));

            Console.WriteLine("Dumping the list:");
            DumpList(list);
          
            // Sorting it by ID
            list.Sort(SortByID);

            Console.WriteLine("Dumping the list:");
            DumpList(list);
          
            // Second Option, using anonimous methods
            // Sorting it by Birthday
            list.Sort(
                  delegate (Item i1, Item i2)
                  {
                        return i1.Birthday.CompareTo(i2.Birthday);
                  }
            );

            Console.WriteLine("Dumping the list:");
            DumpList(list);
          
            //  Wait for response before closing it
            Console.ReadLine();   
    
      }
    public static int SortByID(Item s1, Item s2)
    {
        return s1.ID.CompareTo(s2.ID);
    }
    
      public static void DumpList(List<Item> list)
      {
            foreach(Item l in list)
            {
                  Console.WriteLine(l);
            }
      }
    
}

// Sample Class
 public class Item
{
    public Item(string id, string name)
    {
        this.ID  = id;
        this.Name = name;
        this.Birthday = DateTime.Now;
    }
    public string Name;
    public string ID;
    public DateTime Birthday;
      public override string ToString()
    {
        return String.Format("{0} is born on {1}", this.Name, this.Birthday.ToLocalTime());
    }
}
}