Sorting a Collection of Classes

Creating a collection can save a lot of time and provide a useful way to store a lot of information. But what happens when you want to sort an IEnumerable? Well after a little bit of coding it's possible to create a class that can do this for you and a solution which is both simple and easily reused.

I came across the problem after creating a class which has a number of elements. I then wanted to create a list of this class so I extended IENumerable. Then I noticed that it was not possible to sort this list by a specific element.

I've created a basic sample below to show the solution I used for this.

First, lets set up a basic class and a collection to set the ground for this sample.

public class Person 
{ 
    private string _name; 
    private int _age; 
    
    public string Name { 
        get { return _name; } 
        set { _name = value; } 
    }
 
    public int Age { 
        get { return _age; } 
        set { _age= value; } 
    }
 
    public DeskOrder(string name, int age) { 
        _name = name; 
        _age = age; 
    } 
}

Next a list of those classes

public class PersonList : IEnumerable<Person> 
{ 
    public PersonList() 
    { } 
    
    public List<Person> rows = new List<Person>();

    IEnumerator<Person> IEnumerable<Person>.GetEnumerator() { 
        return rows.GetEnumerator(); 
    } 
    
    IEnumerator IEnumerable.GetEnumerator() { 
        return rows.GetEnumerator(); 
    } 
    
    public Person this[int index] { 
        get { return rows[index]; } 
    } 

    public virtual void Add(Person person) { 
        rows.Add(person); 
    } 
    
    public Person Get(int index) { 
        return rows[index];     
    } 
}

Next, create the sort class. This is the part you want.

class SortField 
{ 
    public enum sortOrderEnum { 
        Descending = 0, 
        Ascending = 1 
    } 

    private sortOrderEnum order; 
    private string name; 

    public string Name { 
        get { return name; } 
        set { name = value; } 
    } 

    public sortOrderEnum Order { 
       get { return order; } 
       set { order = value; } 
    } 

    public SortField(string NameValue, sortOrderEnum OrderValue) { 
       Name = NameValue; 
       Order = OrderValue; 
    } 
}

And that's it! Anytime you want to sort the list of classes you can do it by using the code below...

PersonList personList = new PersonList() 
//.... add some people to the list..... 
List<SortField> sortFields = new List<SortField>();
sortFields.Add(new SortField("Name", SortField.sortOrderEnum.Ascending));
sortFields.Add(new SortField("Age", SortField.sortOrderEnum.Descending));
personList.rows.Sort(new GenericComparer<Person>(sortFields));