using System;

using Flurl;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        var url = "http://www.myapi.com/getstuff".SetQueryParams(new {PageNumber = 1, PageSize = 10});

        Console.WriteLine(url);

        var parameters = new Dictionary<string, object>(){

            {"PageNumber", 1}, 

            {"PageSize", 10}

        };

        var url2 = "http://www.myapi.com/getstuff".SetQueryParams(parameters);

        Console.WriteLine(url);

​

    }

}