using System;

using System.Web;

using Microsoft.AspNetCore.WebUtilities;            

​

public class Program

{

    public static void Main()

    {

        string dantaiNm = "Fuji&Sun";

        string url = @"?a=1&b=John%20Wick";

        string url2 = @"?UketsukeBangoFrom=0000206671&UketsukeBangoTo=0000206671&ReservationStatus=0&DantaiNm=Fuji%20&%20Sun&type=1";

        string url3 = $@"?UketsukeBangoFrom=0000206671&UketsukeBangoTo=0000206671&ReservationStatus=0&DantaiNm={HttpUtility.UrlEncode(dantaiNm)}&type=1";

        PrintParam(url);

        PrintParam(url2);

        PrintParam(url3);

    }

    static void PrintParam(string url) {

        Console.WriteLine("================================");

        var dict = QueryHelpers.ParseQuery(url);

        foreach(var par in dict) {

            Console.WriteLine($"{par.Key} - {par.Value}");

        }

    }

}