Use IComparer : IComparer : Data Structure C# Examples

    
using  System;  
using  System.Collections;  
  
//  Create  an  IComparer  for  Product  objects.  
class  ProductComparer  :  IComparer  {  
    //  Implement  the  IComparable  interface.  
    public  int  Compare(object  obj1,  object  obj2)  {  
        Product  a,  b;  
        a  =  (Product)  obj1;  
        b  =  (Product)  obj2;  
        return  a.name.CompareTo(b.name);  
    }  
}  
  
class  Product  {  
    public  string  name;  
    double  cost;  
    int  onhand;  
  
    public  Product(string  n,  double  c,  int  h)  {  
        name  =  n;  
        cost  =  c;  
        onhand  =  h;  
    }  
  
    public  override  string  ToString()  {  
        return  
            String.Format("{0,-10}Cost:  {1,6:C}    On  hand:  {2}",  
                                        name,  cost,  onhand);  
    }  
}  
  
class  IComparerDemo  {  
    public  static  void  Main()  {  
        ProductComparer  comp  =  new  ProductComparer();  
        ArrayList  inv  =  new  ArrayList();  
          
        //  Add  elements  to  the  list  
        inv.Add(new  Product("A",  5.5,  3));  
        inv.Add(new  Product("B",  8.9,  2));        
        inv.Add(new  Product("C",  3.0,  4));  
        inv.Add(new  Product("D",  1.8,  8));  
  
        Console.WriteLine("Product  list  before  sorting:");  
        foreach(Product  i  in  inv)  {  
            Console.WriteLine("      "  +  i);  
        }  
        Console.WriteLine();  
  
        //  Sort  the  list  using  an  IComparer.  
        inv.Sort(comp);  
  
        Console.WriteLine("Product  list  after  sorting:");  
        foreach(Product  i  in  inv)  {  
            Console.WriteLine("      "  +  i);  
        }  
    }  
}