using System;

using System.Text.RegularExpressions;

public class Program

{

    public static void Main()

    {

        //string pattern = "(?!(([^\"]* \"){2})*[^\"]*$)\n+";

        string pattern = "(?!(([^\"]* \"){2})*[^\"]*$)\n+";

        string replaceBy = " A ";

        string origenWithQuotes = "\"Mustafa Kemal \n Pasa CD No 15;\"IST_TURKIA2\" \"Mustafa \n Kemal Pasa CD No 15 \";\"IST_TURKIA2\"";

        string origenWithoutQuotes = "Mustafa Kemal \n Pasa CD No 15;IST_TURKIA2 \"Mustafa Kemal Pasa CD No 15 \";\"IST_TURKIA2\"";

        Console.WriteLine("String with Quotes    -> " + new Regex(pattern).Replace(origenWithQuotes, replaceBy));

        Console.WriteLine("String without Quotes -> " + new Regex(pattern).Replace(origenWithoutQuotes, replaceBy));

        Console.WriteLine("");

        Console.WriteLine("String with Quotes Function    -> " + RegeReplace(origenWithQuotes,pattern,replaceBy));

        Console.WriteLine("String without Quotes Function -> " + RegeReplace(origenWithoutQuotes,pattern,replaceBy));

        Console.WriteLine("");

        Console.WriteLine("Working");

        Console.WriteLine("");

        Console.WriteLine("String with Quotes Function    -> " + Regex.Replace(origenWithQuotes, @"\""[^\""]*?[\n\r]+[^\""]*?\""", m=>Regex.Replace(m.Value,@"[\n\r]","X")));

        Console.WriteLine("String with Quotes Function    -> " + Regex.Replace(origenWithoutQuotes, @"\""[^\""]*?[\n\r]+[^\""]*?\""", m=>Regex.Replace(m.Value,@"[\n\r]","X")));

    }

    public static String RegeReplace(string Origen, string Patron, string ReemplazarPor)

    {

        string NuevaCadena;

        Regex rgx = new Regex(Patron);

        NuevaCadena = rgx.Replace(Origen, ReemplazarPor);

​

        return NuevaCadena;

    }

​

}