using System;

using System.Linq;

using System.Collections;

using System.Collections.Generic;

public class Program

{

    public class SerializerKey

    {

        public Type Type { get; set; }

        public string Name { get; set; }

    }

​

    public class SerializerKeyComparer : IEqualityComparer<SerializerKey>

    {

        public bool Equals(SerializerKey x, SerializerKey y)

        {

            if (ReferenceEquals(x, y))

            {

                return true;

            }

​

            if (ReferenceEquals(x, null))

            {

                return false;

            }

​

            if (ReferenceEquals(y, null))

            {

                return false;

            }

​

            if (x.GetType() != y.GetType())

            {

                return false;

            }

​

            var tests = new[]

            {

                String.Equals(x.Name, y.Name, StringComparison.InvariantCulture),

                String.Equals(x.Type.FullName, y.Type.FullName, StringComparison.InvariantCulture),

                String.Equals(x.Type.AssemblyQualifiedName, y.Type.AssemblyQualifiedName, StringComparison.InvariantCulture),

                x.Type.Equals(y.Type),

            };

            return tests.All(o => o);

        }

​

        public int GetHashCode(SerializerKey obj)

        {

            unchecked

            {

                var props = new[]

                {

                    obj.Name.GetHashCode(),

                    obj.Type.FullName.GetHashCode(),

                    obj.Type.AssemblyQualifiedName.GetHashCode(),

                    obj.Type.GetHashCode(),

                };

​

                return props.Aggregate((s1, s2) => (s1 * 397) ^ s2);

            }

        }

    }

​

    public static void Main()

    {

        var hashtable = new Hashtable();        

        var hashKey1 = new { Type = typeof(DateTime), Name = string.Empty };

        var hashKey2 = new { Type = typeof(DateTime), Name = string.Empty };

        hashtable[hashKey1] = "1";

        hashtable[hashKey1] = "2";

​

        var dictionary1 = new Dictionary<SerializerKey,string>();       

        var dictionary2 = new Dictionary<SerializerKey,string>(new SerializerKeyComparer());            

        var dictionaryKey1 = new SerializerKey { Type = typeof(DateTime), Name = string.Empty };

        var dictionaryKey2 = new SerializerKey { Type = typeof(DateTime), Name = string.Empty };

​

        dictionary1[dictionaryKey1] = "1";

        dictionary1[dictionaryKey2] = "2";  

        dictionary2[dictionaryKey1] = "1";

        dictionary2[dictionaryKey2] = "2";  

​

        Console.WriteLine("Hashtable");

        Console.WriteLine(hashKey1.GetHashCode());

        Console.WriteLine(hashKey2.GetHashCode());

        Console.WriteLine(hashtable.Count);

        Console.WriteLine();

        Console.WriteLine("Dictionary default implementation");

        Console.WriteLine(dictionaryKey1.GetHashCode());

        Console.WriteLine(dictionaryKey2.GetHashCode());

        Console.WriteLine(dictionary1.Count());

        Console.WriteLine();

​

        Console.WriteLine("Dictionary using SerializerKeyComparer");

        Console.WriteLine(new SerializerKeyComparer().GetHashCode(dictionaryKey1).GetHashCode());

        Console.WriteLine(new SerializerKeyComparer().GetHashCode(dictionaryKey2).GetHashCode());

        Console.WriteLine(dictionary2.Count());

        Console.WriteLine();

​

    }

}