How do I create Extension Methods for string type in Asp.net MVC 2 ?

Question

Hi I'm trying to reach this goal but as far as I am, I've got nothing. I wish to add some static method to string type, which would return new changed string. I've got: using System;

using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Security.Cryptography;
using System.Text;
namespace TestProject.Models
{
    public static class Extension
    {
        public static string md5(this string input)
        {

            MD5 HashAlgorithm = new MD5CryptoServiceProvider();
            Byte[] InputsBytes = Encoding.UTF8.GetBytes(input3);
            Byte[] HashedInput = HashAlgorithm.ComputeHash(InputsBytes);
            return BitConverter.ToString(HashedInput);
        }
    }
}

honestly I just don't know where should it be. I put it in my models catalog but I'm pretty sure it's wrong. Where should it be? And what then? I'd like to use it in this way:

string hashedString = String.md5(input); 

Answer 1

try this : string hashedString = input.md5();

Extension methods are compiler trick the actual call is just a normal static method call.

The compiler just turns the code into:

string hashedString = TestProject.Models.Extentions.md5(input)