The equivalent of select distinct in .Net 2.0

So a while back my bud Ewoudt Kellerman asked me how to take a list of strings in .Net and get a distinct list from them.At the time i was busy and gave a kind of half hearted answer that while it got the job done was long and not very autonomous .I had a few minutes today and whipped this up an thought i would share it with everyone that was looking for a good example on how to use Predicates and Deletegates. I must say before i most this code that it is not the greatest and more a proof of concept and might need some adaptation to use .Also i know there are beter ways to do this in .Net 3.5 and linq but i needed it in .Net 2.0 and i think he did as well.

using System;

using System.Data;

using System.Configuration;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.HtmlControls;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Collections;

using System.Collections.Generic;

///

/// Please dont kill me about the naming or

/// any other standards , this was just a quick

/// class to demonstrate proof of concept.

/// There are surely beter and newer ways to do it

/// in .net 3.5 but this is aimed at the .net 2.0 crowd.

/// Thanks

/// Jameel

///

public class DisctintTest

{

///

/// Constructor For the class nothing special here

/// just calls the test method automatically on creation

/// so that testing is quicker.

///

public DisctintTest()

{

Test();//Call the method

}

//This will contain the last checked string ,starts of as blank

private string lastItem = "";

//The output data that can be inspected to view the cleaned data if u actually want to run this

//example

public List outputData;

///

/// The test method

///

private void Test()

{

//Create a new string list to load with values.

//By using a string list u can add strings that will be sorted

//alphabetically or use numbers which will be sorted by order

List myList = new List();

//Add some data

myList.Add("a");

myList.Add("a");

myList.Add("c");

myList.Add("c");

myList.Add("b");

myList.Add("d");

myList.Add("b");

myList.Add("c");

myList.Add("e");

myList.Add("f");

myList.Add("1");

myList.Add("1");

myList.Add("2");

myList.Add("3");

myList.Add("3");

myList.Add("2");

myList.Add("1");

myList.Add("4");

myList.Add("5");

myList.Add("2");

//Sort the data so that when we remove the data comparisons are easy

myList.Sort();

//Use the removeall to remove the duplicates by using a predicate

//that calls a delegate.

myList.RemoveAll(new Predicate(RemoveDuplicates));

//Set the output data

outputData = myList;

}

///

/// Removes Duplicates from the list based on the last item.

/// It is important to use the sort first or the end list

/// will not be entirely cleaned.

///

///

///

private bool RemoveDuplicates(string currentItem)

{

//Check if the current item we are comapring is the same as the last.

//If the list was sorted and there was a duplicate this would be true.

//And the list would remove the current item

if (currentItem == lastItem)

{

return true;

}

//If not continue and set the last item to the curent item

lastItem = currentItem;

//Return False so as not to delete the current item.

return false;

}

}