Upload CSV File And Read Using ASP.net

steps :

1) Create Simple Web Application Using (ASP.Net with C#).

2) Create Class CSVReader (CSVReader.cs)

   1: using System;

   2: using System.Data;

   3: using System.Configuration;

   4: using System.Web;

   5: using System.Web.Security;

   6: using System.Web.UI;

   7: using System.Web.UI.WebControls;

   8: using System.Web.UI.WebControls.WebParts;

   9: using System.Web.UI.HtmlControls;

  10: using System.IO;

  11: using System.Text;

  12: using System.Collections;

  13:  

  14: public class CSVReader

  15: {

  16:     //

  17:     private Stream objStream;

  18:     private StreamReader objReader;

  19:  

  20:     //add name space System.IO.Stream

  21:     public CSVReader(Stream filestream) : this(filestream, null) { }

  22:  

  23:     public CSVReader(Stream filestream, Encoding enc)

  24:     {

  25:         this.objStream = filestream;

  26:         //check the Pass Stream whether it is readable or not

  27:         if (!filestream.CanRead)

  28:         {

  29:             return;

  30:         }

  31:         objReader = (enc != null) ? new StreamReader(filestream, enc) : new StreamReader(filestream);

  32:     }

  33:     //parse the Line

  34:     public string[] GetCSVLine()

  35:     {

  36:         string data = objReader.ReadLine();

  37:         if (data == null) return null;

  38:         if (data.Length == 0) return new string[0];

  39:         //System.Collection.Generic

  40:         ArrayList result = new ArrayList();

  41:         //parsing CSV Data

  42:         ParseCSVData(result, data);

  43:         return (string[])result.ToArray(typeof(string));

  44:     }

  45:  

  46:     private void ParseCSVData(ArrayList result, string data)

  47:     {

  48:         int position = -1;

  49:         while (position < data.Length)

  50:             result.Add(ParseCSVField(ref data, ref position));

  51:     }

  52:  

  53:     private string ParseCSVField(ref string data, ref int StartSeperatorPos)

  54:     {

  55:         if (StartSeperatorPos == data.Length - 1)

  56:         {

  57:             StartSeperatorPos++;

  58:             return "";

  59:         }

  60:  

  61:         int fromPos = StartSeperatorPos + 1;

  62:         if (data[fromPos] == '"')

  63:         {

  64:             int nextSingleQuote = GetSingleQuote(data, fromPos + 1);

  65:             int lines = 1;

  66:             while (nextSingleQuote == -1)

  67:             {

  68:                 data = data + "\n" + objReader.ReadLine();

  69:                 nextSingleQuote = GetSingleQuote(data, fromPos + 1);

  70:                 lines++;

  71:                 if (lines > 20)

  72:                     throw new Exception("lines overflow: " + data);

  73:             }

  74:             StartSeperatorPos = nextSingleQuote + 1;

  75:             string tempString = data.Substring(fromPos + 1, nextSingleQuote - fromPos - 1);

  76:             tempString = tempString.Replace("'", "''");

  77:             return tempString.Replace("\"\"", "\"");

  78:         }

  79:  

  80:         int nextComma = data.IndexOf(',', fromPos);

  81:         if (nextComma == -1)

  82:         {

  83:             StartSeperatorPos = data.Length;

  84:             return data.Substring(fromPos);

  85:         }

  86:         else

  87:         {

  88:             StartSeperatorPos = nextComma;

  89:             return data.Substring(fromPos, nextComma - fromPos);

  90:         }

  91:     }

  92:  

  93:     private int GetSingleQuote(string data, int SFrom)

  94:     {

  95:         int i = SFrom - 1;

  96:         while (++i < data.Length)

  97:             if (data[i] == '"')

  98:             {

  99:                 if (i < data.Length - 1 && data[i + 1] == '"')

 100:                 {

 101:                     i++;

 102:                     continue;

 103:                 }

 104:                 else

 105:                     return i;

 106:             }

 107:         return -1;

 108:     }

 109: }

 110:  

3) put below control in to the aspx page.

<table>
 <tr>
  <td>
   <asp:FileUpload ID="FileUpload1" runat="server" />
  </td>
  <td>
   <asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Upload CSV" />
  </td>
 </tr>
 <tr>
   <td colspan="2">
    <asp:Label ID="lblMsg" Text="Please Select Proper File" runat="server" BorderColor="White"
         Font-Bold="True" ForeColor="Red" Visible="false"></asp:Label>
   </td>
 </tr>
 <tr>
   <td>
    <asp:GridView ID="gv" runat="server"></asp:GridView>
   </td>
 </tr>
</table>

4) In Code Behind File Put Below Code.

   1: protected void Button1_Click(object sender, EventArgs e)

   2:    {

   3:        if (FileUpload1.PostedFile.FileName == string.Empty)

   4:        {

   5:            lblMsg.Visible = true;

   6:            return;

   7:        }

   8:        else

   9:        { 

  10:            //save the file 

  11:            //restrict user to upload other file extenstion

  12:            string[] FileExt = FileUpload1.FileName.Split('.');

  13:            string FileEx = FileExt[FileExt.Length - 1];

  14:            if (FileEx.ToLower() == "csv")

  15:            {

  16:                FileUpload1.SaveAs(Server.MapPath("CSVLoad//" + FileUpload1.FileName));

  17:            }

  18:            else

  19:            {

  20:                lblMsg.Visible = true;

  21:                return;

  22:            }

  23:        }

  24:  

  25:        //create object for CSVReader and pass the stream

  26:        CSVReader reader = new CSVReader(FileUpload1.PostedFile.InputStream);

  27:        //get the header

  28:        string[] headers = reader.GetCSVLine();        

  29:        DataTable dt = new DataTable();

  30:        //add headers

  31:        foreach (string strHeader in headers)

  32:            dt.Columns.Add(strHeader);

  33:  

  34:        string[] data;

  35:        while ((data = reader.GetCSVLine()) != null)

  36:            dt.Rows.Add(data);

  37:        //bind gridview

  38:        gv.DataSource = dt;

  39:        gv.DataBind();

  40:        

  41:    }

5) create Folder In WebSite CSVLoad for Save Uploaded CSV File.

Thnx