how to count the number of columns in a text file using c#

columnCount.cs

public static int columnCount(string filepath) 
        {
            int numColumns = 0;
            using(var reader = File.OpenText(filepath))
            {
                while(reader.ReadLine() != null )
                {
                    string data = System.IO.File.ReadAllText(filepath);

                    // split the text
                    data = data.Replace("\n", "\r");
                    string[] lines = data.Split(new char[] { '\r' }, StringSplitOptions.RemoveEmptyEntries);

                    // to get how many rows and columns
                    //int numRows = lines.Length;
                    numColumns = lines[0].Split(',').Length;
                }
            }

            return numColumns;
        }