using System;

using System.Web;

using System.IO;

public class Program

{

    public static void Main()

    {

        string myString = "<b>Hello World</b>";

        // Encode the string.

        string myEncodedString = HttpUtility.HtmlEncode(myString);

​

        Console.WriteLine($"HTML Encoded string is: {myEncodedString}");

        StringWriter myWriter = new StringWriter();

​

        // Decode the encoded string.

        HttpUtility.HtmlDecode(myEncodedString, myWriter);

​

        string myDecodedString = myWriter.ToString();

        Console.Write($"Decoded string of the above encoded string is: {myDecodedString}");

​

    }

}