using System;

using System.Web;

using System.Text;

using System.Collections.Specialized;

​

public class Program

{

    public static void Main()

    {

        var toQuery = HttpUtility.ParseQueryString("");

        toQuery.Add("hello","world");

        toQuery.Add("cafe","café");

        toQuery.Add("armoured","blindée");

        toQuery.Add("foot","fuß");

        toQuery.Add("BnH","B&H");

        toQuery.Add("All","100%");

        toQuery.Add("Empty","");

        toQuery.Add("Swear","!\"£$%^&*()_+-=[]{};'#:@~,./<>?\\|");

        toQuery.Add("VeryÐôďğÝ","VeryDodgy");

​

        var def  = defaulttostring(toQuery);

        var matt =    matttostring(toQuery);

        // note this edits the collection so put it last

        var rich = richardtostring(toQuery);

        Console.WriteLine(def);

        Console.WriteLine();

        Console.WriteLine(matt);

        Console.WriteLine();

        Console.WriteLine(rich);

    }

    private static string defaulttostring(NameValueCollection toQuery)

    {

        return toQuery.ToString();

    }

​

    private static string matttostring(NameValueCollection toQuery)

    {

        var sb = new StringBuilder();

        foreach (string key in toQuery.AllKeys) {

            sb.Append(HttpUtility.UrlEncode(key));

            sb.Append("=");

            sb.Append(HttpUtility.UrlEncode(toQuery[key]));

            sb.Append("&");

        }

        // remove last "&" when we turn it into a string

        return sb.ToString(0,sb.Length - "&".Length);

    }

    // note this edits the collection so put it last

    private static string richardtostring(NameValueCollection toQuery)

    {

        foreach (string key in toQuery.AllKeys) {

            toQuery[key] = HttpUtility.UrlEncode(toQuery[key]);

        }

        return Uri.UnescapeDataString(toQuery.ToString());

    }

​

}