// C# Extension Method

// Doc: https://csharp-extension.com/en/method/1002123/string-htmlencode

​

// @nuget: Z.ExtensionMethods

​

using System;

using System.IO;

​

public class Program

{   

    public static void Main()

    {   

        string input = "<script>alert(\"Hello World!\");</script>";

​

        //C# Extension Method: String - HtmlEncode

        var output = input.HtmlEncode();

        Console.WriteLine(output);

        TextWriter writer = File.CreateText("test.txt");

        //C# Extension Method: String - HtmlEncode

        input.HtmlEncode(writer);

        writer.Close();

        Console.WriteLine(File.ReadAllText("test.txt"));

    }

}