CODEWITHSUNDEEP
c#listsortingicomparable
Asdfg
Asdfg

Reputation: 12213

list is not getting sorted using IComparable<T>

This is my abstract base class:

public abstract class BaseDataModel<T> : System.IComparable<T> where T : BaseDataModel<T>
{
    public int ID { get; set; }
    public int CreatedBy { get; set; }
    public DateTime CreatedOn { get; set; }
    public int? UpdatedBy { get; set; }
    public DateTime? UpdatedOn { get; set; }


    #region IComparable<T> Members

    public virtual int CompareTo(T other)
    {
        return ID.CompareTo(other.ID);
    }

    #endregion
}

This class represents Person and imherits from the BaseDataModel class.

public class Person : BaseDataModel<Person>
    {
        public string Name { get; set; }
    }

But when i am trying to sort the List using sort() method, it doesnt work. It returns the sorted list with 2 objects but all the properties in those objects are null.

    static void Main(string[] args)
    {
        List<Person> pList = new List<Person>();

        Person p = new Person();
        p.ID=2;
        p.Name="Z";
        pList.Add(p);

        Person p1 = new Person();
        p.ID = 1;
        p.Name = "A";
        pList.Add(p1);

        pList.Sort();





        Console.Read();

    }
}

What is the problem here?

Upvotes: 1

Views: 137

Answers (2)

Reed Copsey
Reed Copsey

Reputation: 564641

The problem is here:

  Person p = new Person();
    p.ID=2;
    p.Name="Z";
    pList.Add(p);

    Person p1 = new Person();
    p.ID = 1;
    p.Name = "A";
    pList.Add(p1);

This should be:

  Person p = new Person();
    p.ID=2;
    p.Name="Z";
    pList.Add(p);

    Person p1 = new Person();
    // Change properties of p1, not p!
    p1.ID = 1;
    p1.Name = "A";
    pList.Add(p1);

Upvotes: 2

SLaks
SLaks

Reputation: 887777

You're setting the properties of p twice; you never set p1.ID.

Upvotes: 3

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