How to decode the email quoted printable encoded in C#

Question

I have took a look for many solution here and still not found the work solution to decode email quoted printable.

Example input:

*** Hello, World *** =0D=0AURl: http://w=
ww.example.com?id=3D=
27a9dca9-5d61-477c-8e73-a76666b5b1bf=0D=0A=0D=0A  
Name: Hello World=0D=0A
Phone: 61234567890=0D=0A
Email: hello@test.com=0D=0A=0D=0A

and the example expected output is:

*** Hello, World *** 
URl: http://www.example.com?id=27a9dca9-5d61-477c-8e73-a76666b5b1bf


Name: Hello World

Phone: 61234567890

Email: hello@test.com

Following www.webatic.com/quoted-printable-convertor are correct rendering.

Do somebody have an idea to solve this problem in C#?

Answer 1

Try the below Snippet to decode Quoted Printable encoding

class Program
{

    public static string DecodeQuotedPrintable(string input, string charSet)
    {
        Encoding enc;

        try
        {
            enc = Encoding.GetEncoding(charSet);
        }
        catch
        {
            enc = new UTF8Encoding();
        }

        var occurences = new Regex(@"(=[0-9A-Z]{2}){1,}", RegexOptions.Multiline);
        var matches = occurences.Matches(input);

        foreach (Match match in matches)
        {
            try
            {
                byte[] b = new byte[match.Groups[0].Value.Length / 3];
                for (int i = 0; i < match.Groups[0].Value.Length / 3; i++)
                {
                    b[i] = byte.Parse(match.Groups[0].Value.Substring(i * 3 + 1, 2), System.Globalization.NumberStyles.AllowHexSpecifier);
                }
                char[] hexChar = enc.GetChars(b);
                input = input.Replace(match.Groups[0].Value, new String(hexChar));
            }
            catch
            { ;}
        }
        input = input.Replace("?=", "");

        return input;
    }

    static void Main(string[] args)
    {
        string sData = @"*** Hello, World *** =0D=0AURl: http://www.example.com?id=3D=27a9dca9-5d61-477c-8e73-a76666b5b1bf=0D=0A=0D=0A  
Name: Hello World=0D=0A
Phone: 61234567890=0D=0A
Email: hello@test.com=0D=0A=0D=0A";

        Console.WriteLine(DecodeQuotedPrintable(sData,"utf-8"));
        Console.ReadLine();
    }

}

Running code is avaliable in dotnetfiddle

Taken the Snippet from this link