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 back to "Commit\r\n\r" as a .net string. I was hoping for a string.Unescape() and string.Escape() method pair, but it doesn't seem to exist. Am I going to have to write my own? or is there a more simple way to do this?

Answer 1

So is your problem that you are trying to convert to and from ASCII? Because it's not at all clear what you want to "escape" or "unescape".

Encoding.ASCII will return an encoding object that you can use to convert between Unicode and ASCII (GetBytes to convert to ASCII from a .Net String,, GetString to convert from an array of ASCII bytes to a string ).

Answer 2

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 StringEscape
   {
       public static string EscapeStringChars( 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();
   }
   
   
   }
   

Answer 3

System.Text.Regex.Unescape(@"\r\n\t\t\t\t\t\t\t\t\tHello world!")