Code for Encoding / Decoding QuotedPrintable.

Question

This method Encodes text in QuotedPrintable format.

public static string EncodeQuotedPrintable(string value) { if (string.IsNullOrEmpty(value)) return value; StringBuilder builder = new StringBuilder(); byte[] bytes = Encoding.UTF8.GetBytes(value); foreach (byte v in bytes) { // The following are not required to be encoded: // - Tab (ASCII 9) // - Space (ASCII 32) // - Characters 33 to 126, except for the equal sign (61). if ((v == 9) || ((v >= 32) && (v <= 60)) || ((v >= 62) && (v <= 126))) { builder.Append(Convert.ToChar(v)); } else { builder.Append('='); builder.Append(v.ToString("X2")); } } char lastChar = builder[builder.Length - 1]; if (char.IsWhiteSpace(lastChar)) { builder.Remove(builder.Length - 1, 1); builder.Append('='); builder.Append(((int)lastChar).ToString("X2")); } return builder.ToString(); } 

This Method Decode QuotedPrintable Text to a String

 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("?=", "").Replace("\r\n", ""); return input; }