How can I Unescape and Reescape strings in .net?

Question

I need a TextBox on a WPF control that can take in text like Commit\\r\\n\\r (which is the .net string \"Commit\\\\r\\\\n\\\\r\") and convert it ba

Answer 1

Hans's code, improved version.

1. Made it use StringBuilder - a real performance booster on long strings

2. Made it an extension method

   public static class StringUnescape
   {
       public static string Unescape(this string txt)
       {
           if (string.IsNullOrEmpty(txt)) { return txt; }
           StringBuilder retval = new StringBuilder(txt.Length);
           for (int ix = 0; ix < txt.Length; )
           {
               int jx = txt.IndexOf('\\', ix);
               if (jx < 0 || jx == txt.Length - 1) jx = txt.Length;
               retval.Append(txt, ix, jx - ix);
               if (jx >= txt.Length) break;
               switch (txt[jx + 1])
               {
                   case 'n': retval.Append('\n'); break;  // Line feed
                   case 'r': retval.Append('\r'); break;  // Carriage return
                   case 't': retval.Append('\t'); break;  // Tab
                   case '\\': retval.Append('\\'); break; // Don't escape
                   default:                                 // Unrecognized, copy as-is
                       retval.Append('\\').Append(txt[jx + 1]); break;
               }
               ix = jx + 2;
           }
           return retval.ToString();
       }
   }