The Comma Separated Value (CSV) file contains data that (as the name suggests) are separated by commas.  In C# they can easily be split into an array by using Data.Split(',').  The problem occurs when data contains a comma.  To overcome this problem, any data that contains comma is enclosed with double quotes ("").

The following function can split a csv data into array and preserve the double quoted fields.  This is a sample function, you pass a single comma separated line of data.  By default the separator is a comma.

I have used this in a project and seems to be working.  Please do your own testing before using it and if you encounter any problem or issues let me know, so I can fix it.

        private string[] csvParser(string csv, char separator = ',')
        {
            List <string> parsed = new <string>();
            string[] temp = csv.Split(separator);
            int counter = 0;
            string data = string.Empty;
            while (counter < temp.Length)
            {
                data = temp[counter].Trim();
                if (data.Trim().StartsWith("\""))
                {
                    bool isLast = false;
                    while (!isLast && counter < temp.Length)
                    {
                        data += separator.ToString() + temp[counter + 1];
                        counter++;
                        isLast = (temp[counter].Trim().EndsWith("\""));
                    }
                }
                parsed.Add(data);
                counter++;
            }

            return parsed.ToArray();

        }

Test data:
Only One Field
First, Second
"First-A, First-B", Second, Third, Fourth, Fifth
First, "Second-A, Second-B", Third, Fourth, Fifth
First, "Second-A, Second-B, Second-C", "Third-A, Third-B", Fourth, Fifth
First, Second, Third, Fourth, "Fifth-A, Fifth-B"
"First-A, First-B, First-C", "Second-A, Second-B, Second-C", Third, Fourth, "Fifth-A, Fifth-B, Fifth-C"
"First-A, First-B, First-C", "Second-A, Second-B, Second-C", "Third-A, Third-B, Third-C, Third-D", "Fourth-A, Fourth-B, Fourth-C, Fourth-D, Fourth-E", "Fifth-A, Fifth-B, Fifth-C"