/App_Code/DataFlow.cs

using System;

using System.Data;

using System.Configuration;

using System.Collections;

using System.Linq;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.HtmlControls;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Xml.Linq;

using System.IO;

using System.Collections.Generic;

using System.Text;

using System.Data.SqlClient;

using System.Text.RegularExpressions;





/// <summary>

/// Summary description for DataFlow

/// </summary>

public class DataFlow

{

    

	public DataFlow()

	{

		//

		// TODO: Add constructor logic here

		//  

	}

    public static DataTable csvToDataTable(string file, bool isRowOneHeader)

    {

        string head;

        DataTable csvDataTable = new DataTable();

        //no try/catch - add these in yourselfs or let exception happen

        String[] csvData = File.ReadAllLines(file);



        // Static method:

        Regex re = new Regex("^[-'a-zA-Z]*$");



        // Name does not match schema



        //if no data in file ‘manually’ throw an exception

        if (csvData.Length == 0)

        {

            throw new Exception("CSV File Appears to be Empty");

        }

        String[] headings = csvData[0].Split(',');



        int index = 0; //will be zero or one depending on isRowOneHeader

        if (isRowOneHeader) //if first record lists headers

        {

            index = 1; //so we won’t take headings as data

            //for each heading

            for (int i = 0; i < headings.Length; i++)

            {

                string a = headings[0];



                //replace spaces with underscores for column names

                headings[i] = headings[i].Replace(" ", "_");

                //add a column for each heading

                head = headings[i].ToString();

                csvDataTable.Columns.Add(headings[i], typeof(string));

            }

        }

        else //if no headers just go for col1, col2 etc.

        {

            csvDataTable.Columns.Add("Mobile Number", typeof(string));

            //csvDataTable.Columns.Add("EmailId", typeof(string));

            //csvDataTable.Columns.Add("First Name", typeof(string));

            //csvDataTable.Columns.Add("Last Name", typeof(string));

        }



        //populate the DataTable

        for (int i = index; i < csvData.Length; i++)

        {

            //create new rows

            DataRow row = csvDataTable.NewRow();



            for (int j = 0; j < headings.Length; j++)

            {



                //fill them

                row[j] = csvData[i].Split(',')[j];



            }

            //add rows to over DataTable

            csvDataTable.Rows.Add(row);

        }



        string check_special_characters = CheckString(File.ReadAllText(file));

        if (check_special_characters.Length == 0)

        {

            return csvDataTable;

        }

        else

        {

            csvDataTable = null;

            return csvDataTable;

        }

    }



     public static string CheckString(string text)  

         {

           Regex oRegex = new Regex(@"[<;#$^/>]+", RegexOptions.IgnoreCase);  

           Match oMatch = oRegex.Match(text);  

           oRegex = null;  

         

          if (oMatch.Success)  

             return "Please exclude special characters";  

           else  

             return "";  

         }  

    public void ExportCSV(DataTable data, String filename)

    {

        HttpContext context = HttpContext.Current;

        context.Response.Clear();

        context.Response.ContentType = "text/csv";

        context.Response.AddHeader("Content-Disposition", "attachment;filename=" + filename + ".csv");

        //write column header names

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

        {

            if (i > 0)

            {

                context.Response.Write(",");

            }

            context.Response.Write(data.Columns[i].ColumnName);



        }

        context.Response.Write(Environment.NewLine);



        foreach (DataRow row in data.Rows)

        {

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

            {

                if (i > 0)

                {

                    context.Response.Write(",");

                }

                context.Response.Write(row[i].ToString());

            }

            context.Response.Write(Environment.NewLine);

        }

        context.Response.End();



    }

    public void ExportTXT(DataTable data, String filename)

    {

        HttpContext context = HttpContext.Current;

        context.Response.Clear();

        context.Response.ContentType = "text/csv";

        context.Response.AddHeader("Content-Disposition", "attachment;filename=" + filename + ".txt");

        //write column header names

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

        {

            if (i > 0)

            {

                context.Response.Write(",");

            }

            context.Response.Write(data.Columns[i].ColumnName);



        }

        context.Response.Write(Environment.NewLine);



        foreach (DataRow row in data.Rows)

        {

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

            {

                if (i > 0)

                {

                    context.Response.Write(",");

                }

                context.Response.Write(row[i].ToString());

            }

            context.Response.Write(Environment.NewLine);

        }

        context.Response.End();



    }

    public static void Export(string fileName, GridView gv)

    {

        HttpContext.Current.Response.Clear();

        HttpContext.Current.Response.AddHeader(

            "content-disposition", string.Format("attachment; filename={0}", fileName));

        HttpContext.Current.Response.ContentType = "application/ms-excel";



        using (StringWriter sw = new StringWriter())

        {

            using (HtmlTextWriter htw = new HtmlTextWriter(sw))

            {

                //  Create a form to contain the grid

                Table table = new Table();

                table.GridLines = gv.GridLines; 



                //  add the header row to the table

                if (gv.HeaderRow != null)

                {

                    DataFlow.PrepareControlForExport(gv.HeaderRow);

                    table.Rows.Add(gv.HeaderRow);

                }

                //  add each of the data rows to the table

                foreach (GridViewRow row in gv.Rows)

                {

                    DataFlow.PrepareControlForExport(row);

                    table.Rows.Add(row);

                }



                //  add the footer row to the table

                if (gv.FooterRow != null)

                {

                    DataFlow.PrepareControlForExport(gv.FooterRow);

                    table.Rows.Add(gv.FooterRow);

                }



                //  render the table into the htmlwriter

                table.RenderControl(htw);



                //  render the htmlwriter into the response

                HttpContext.Current.Response.Write(sw.ToString());

                HttpContext.Current.Response.End();

            }

        }

    }



    /// <summary>

    /// Replace any of the contained controls with literals

    /// </summary>

    /// <param name="control"></param>

    private static void PrepareControlForExport(Control control)

    {

        for (int i = 0; i < control.Controls.Count; i++)

        {

            Control current = control.Controls[i];

            if (current is LinkButton)

            {

                control.Controls.Remove(current);

                control.Controls.AddAt(i, new LiteralControl((current as LinkButton).Text));

            }

            else if (current is ImageButton)

            {

                control.Controls.Remove(current);

                control.Controls.AddAt(i, new LiteralControl((current as ImageButton).AlternateText));

            }

            else if (current is HyperLink)

            {

                control.Controls.Remove(current);

                control.Controls.AddAt(i, new LiteralControl((current as HyperLink).Text));

            }

            else if (current is DropDownList)

            {

                control.Controls.Remove(current);

                control.Controls.AddAt(i, new LiteralControl((current as DropDownList).SelectedItem.Text));

            }

            else if (current is CheckBox)

            {

                control.Controls.Remove(current);

                control.Controls.AddAt(i, new LiteralControl((current as CheckBox).Checked ? "True" : "False"));

            }



            if (current.HasControls())

            {

                DataFlow.PrepareControlForExport(current);

            }

        }

    }

}