using System;
using System.Net;
public class Program
{
public static void Main()
string testString = "http://10.208.15.10:8090/api/627600201/CheckCostAccount/3015294/mbl%231";
//.Net 4.0+
Console.WriteLine("WebUtility.HtmlEncode: " + WebUtility.HtmlEncode(testString));
}