using System;

using System.Data;

using System.Text;

​

public class Program

{

    public static void Main()

    {

        Console.WriteLine("\nPasso 01 (table original):");

        DataTable data = GetTable();

        Console.WriteLine(fnDataTablesToCsv(data));

        Console.WriteLine("\nPasso 02 (table with new autonumeric column):");       

        //fnDataTableAddColumnAutoNumber(data,"SEQ");       

        fnDataTableAddColumnSequenceNumber(data,"SEQ" ,1, 1);       

        fnDataTableAddColumnSequenceNumber(data,"N");       

        fnDataTableAddColumnSequenceNumber(data,"P10" ,10, 10);     

        Console.WriteLine(fnDataTablesToCsv(data));

        Console.WriteLine("\nPasso 03 Teste Nao gera numeracao automatica quando adiciona novos itens:");       

        DataTable dataN = data.Copy();

        foreach (DataRow dr in  dataN.Rows) {

            dr["SEQ"]=0;

            data.Rows.Add(dr.ItemArray);

        }

        Console.WriteLine(fnDataTablesToCsv(data));

        Console.WriteLine("\nPasso 03 TesteN Tabela de copia:");        

        Console.WriteLine(fnDataTablesToCsv(dataN));

        //Console.WriteLine("\nPasso 03 - Example, convert to CSV with comma inside row:");

        //Console.WriteLine(fnDataTablesToCsvSimple(data));     

        return;

    }

    public static string fnDataTableAddColumnSequenceNumber(DataTable dt, String ColumnName, int Inicio = 1, int Step = 1)

        {

​

            try

            {

                DataColumn column = new DataColumn();

                column.ColumnName = ColumnName;

                column.DataType = System.Type.GetType("System.Int32");

                //Nao gera autonumeracao automatica: --> //column.AutoIncrement = true; //column.AutoIncrementSeed = 0; //column.AutoIncrementStep = 1;

                dt.Columns.Add(column);

                int index = Inicio;

                foreach (DataRow row in dt.Rows)

                {                    

                    row[column] = index;

                    index = (index + Step);

                }

                return "OK";

            }

            catch (Exception ex)

            {

                return ex.Message;

            }

        }

​

    public  static string fnDataTablesToCsv( DataTable dataTable) {

        StringBuilder sbData = new StringBuilder();

        try

        {

​

            // Only return Null if there is no structure.

            if (dataTable.Columns.Count == 0){ return null; }

            //Columns

            foreach (var col in dataTable.Columns) {

                if (col == null)

                    sbData.Append(",");

                else

                    sbData.Append("\"" + col.ToString().Replace("\"", "\"\"") + "\",");

            }

            //Data Transformation

            sbData.Replace(",", System.Environment.NewLine, sbData.Length - 1, 1);

​

            //Rows 

            foreach (DataRow dr in dataTable.Rows) {

                foreach (var column in dr.ItemArray) {

                    if (column == null)

                        sbData.Append(",");

                    else

                        sbData.Append("\"" + column.ToString().Replace("\"", "\"\"") + "\",");

                }

                sbData.Replace(",", System.Environment.NewLine, sbData.Length - 1, 1);

            }

​

            return sbData.ToString();           

        }

        catch (Exception)

        {

            return null;

        }

    }

    public static string fnDataTablesToCsvSimple(DataTable dt){

        StringBuilder sb = new StringBuilder();

​

        foreach (DataColumn col in dt.Columns)

        {

            sb.Append(col.ColumnName + ',');

        }

​

        sb.Remove(sb.Length - 1, 1);

        sb.Append(Environment.NewLine);

​

        foreach (DataRow row in dt.Rows)

        {

            for (int i = 0; i < dt.Columns.Count; i++)

            {

                sb.Append(row[i].ToString() + ",");

            }

​

            sb.Append(Environment.NewLine);

        }

        return sb.ToString();

    }

    public static string fnDataTableAddColumnAutoNumber(DataTable dt, String ColumnName,int Inicio = 1){

        try

        {

            DataColumn column = new DataColumn();

            column.ColumnName = ColumnName;

            column.DataType = System.Type.GetType("System.Int32");

            column.AutoIncrement = true;

            column.AutoIncrementSeed = 0;

            column.AutoIncrementStep = 1;

            dt.Columns.Add(column);

            int index = Inicio;

            foreach (DataRow row in dt.Rows)

            {

                row[column]= index++;

            }

            return "OK";

​

        }

        catch (Exception ex)

        {

            return ex.Message;

        }

    }

    static DataTable GetTable()

    {

        // Here we create a DataTable with four columns.

        DataTable table = new DataTable();

        table.Columns.Add("Dosage", typeof(int));

        table.Columns.Add("Drug", typeof(string));

        table.Columns.Add("Patient", typeof(string));

        table.Columns.Add("Date", typeof(DateTime));

​

        // Here we add five DataRows.

        table.Rows.Add(25, "Indocin", "David", DateTime.Now);

        table.Rows.Add(50, "Enebrel", "Sam", DateTime.Now);

        table.Rows.Add(10, "Hydralazine", "Christoff", DateTime.Now);

        table.Rows.Add(21, "Combivent", "Janet", DateTime.Now);

        table.Rows.Add(100, "Dilantin", "Melanie", DateTime.Now);

        table.Rows.Add(51, "Fernando,Luiz", "Melanie,,,,,,", DateTime.Now);

        return table;

    }

    //public static DataTable fnDataTableAccColumnAutonumber(string json){

    //  DataTable dt = (DataTable)JsonConvert.DeserializeObject(json, (typeof(DataTable)));

    //  return dt;

    //}

}