how to update values in excel

Question

0.00/5 (No votes)

See more:

Hi,

My module is to insert values in the front end and want to save that in an excel sheet.. I passed the textbox values to grid and passed the grid to excel..
After rntering the values are passed in grid, i ll give save and it ll be saved in my excel..
If i reopen the application and enter the values and give save, then the new values are not updating in the same excel sheet.. Its again opening in a different sheet..

I want the values to be updated in the same excel sheet..
This is how my frontend look :

VB

Name --------------
Age --------------

[submit] [save]

after giving submit, the grid appears with the value and if i click save, the excel sheet populates.

Below is my code. :

VB

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using System.Reflection;
using System.IO;

public partial class _Default : System.Web.UI.Page
{
    //Microsoft.Office.Interop.Excel.Application oXL;
    //Microsoft.Office.Interop.Excel._Workbook oWB;
    //Microsoft.Office.Interop.Excel._Worksheet oSheet; 
    private DataTable _dt;

    public DataTable dt
    {
        get
        {
            return _dt;
        }
        set
        {
            _dt = value;
        }
    }

    protected void Page_Load(object sender, EventArgs e)
    {
        
        if (!IsPostBack)
        {
            DataTable dt = new DataTable();
            dt.Columns.Add("CodeID", typeof(string));
            dt.Columns.Add("Content", typeof(string));
            dt.Columns.Add("MappingCode", typeof(string));
            Session["dt"] = dt;
        }
        _dt = (DataTable)Session["dt"];
      

           }
    private void BindGrid()
    {
        GridView1.DataSource = dt;
        GridView1.DataBind();
    }

    private void ExporttoExcel(DataTable table)
    {

        HttpContext.Current.Response.Clear();
        HttpContext.Current.Response.ClearContent();
        HttpContext.Current.Response.ClearHeaders();
        HttpContext.Current.Response.Buffer = true;
        HttpContext.Current.Response.ContentType = "application/ms-excel";
        //HttpContext.Current.Response.ContentType = "application/ms-word";
        HttpContext.Current.Response.Write(@"<!DOCTYPE HTML PUBLIC ""-//W3C//DTD HTML 4.0 Transitional//EN"">");
        HttpContext.Current.Response.AddHeader("Content-Disposition", "attachment;filename=Reports.xls");
        // HttpContext.Current.Response.AddHeader("Content-Disposition", "attachment;filename=Reports.doc");
        HttpContext.Current.Response.Charset = "utf-8";
        HttpContext.Current.Response.ContentEncoding = System.Text.Encoding.GetEncoding("windows-1250");
        HttpContext.Current.Response.Write("<font style='font-size:10.0pt; font-family:Calibri;'>");
        HttpContext.Current.Response.Write("<BR><BR><BR>");
        HttpContext.Current.Response.Write("<Table border='1' bgColor='#ffffff' borderColor='#000000' cellSpacing='0' cellPadding='0' style='font-size:10.0pt; font-family:Calibri; background:white;'> <TR>");
        int columnscount = GridView1.Columns.Count;

        for (int j = 0; j < columnscount; j++)
        {
            HttpContext.Current.Response.Write("<Td>");
            HttpContext.Current.Response.Write("");
            HttpContext.Current.Response.Write(GridView1.Columns[j].HeaderText.ToString());
            HttpContext.Current.Response.Write("");
            HttpContext.Current.Response.Write("</Td>");
        }
        HttpContext.Current.Response.Write("</TR>");
        foreach (DataRow row in table.Rows)
        {
            HttpContext.Current.Response.Write("<TR>");
            for (int i = 0; i < table.Columns.Count; i++)
            {
                HttpContext.Current.Response.Write("<Td>");
                HttpContext.Current.Response.Write(row[i].ToString());
                HttpContext.Current.Response.Write("</Td>");
            }

            HttpContext.Current.Response.Write("</TR>");
        }
        HttpContext.Current.Response.Write("</Table>");
        HttpContext.Current.Response.Write("</font>");
        HttpContext.Current.Response.Flush();
        HttpContext.Current.Response.End();
    }
    protected void Btn_Export_Click(object sender, EventArgs e)
    {
                Response.Clear();
        Response.AddHeader("content-disposition", "attachment;filename=GridView1.xls");
        Response.Charset = "";
        Response.ContentType = "application/vnd.xls";
        StringWriter StringWriter = new System.IO.StringWriter();
        HtmlTextWriter HtmlTextWriter = new HtmlTextWriter(StringWriter);
        GridView1.RenderControl(HtmlTextWriter);
        Response.Write(StringWriter.ToString());
        Response.End();
           }
    protected void btnSubmit_Click(object sender, EventArgs e)
    {
        DataTable dt = (DataTable)Session["dt"];
        DataRow drToGrid = dt.NewRow();
        drToGrid["CodeID"] = txtCodeID.Text;
        drToGrid["Content"] = txtContent.Text;
        drToGrid["MappingCode"] = txtMappingCode.Text;

        dt.Rows.Add(drToGrid);
        GridView1.DataSource = dt;
        GridView1.DataBind();
        BindGrid();
        txtCodeID.Text = txtContent.Text = txtMappingCode.Text = string.Empty;
           

    }
    


    public override void VerifyRenderingInServerForm(Control control)
    {

        /* Verifies that the control is rendered */

    }
   
}

Can someone please help me or give me any idea..

Thanks a ton. :)

Anusha

Posted 13-Sep-12 18:06pm

Anusha Sridhar

Add a Solution

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Gautam Raithatha · Accepted Answer · 2012-09-13T18:28:00

hi....

u can make manipulate data in excel file in the same way u do with sql server or any other database. There will be only some minor changes. First of all, connection string will change. for e.g. ur excel file is "test.xlsx" in D drive, then:

Provider=Microsoft.ACE.OLEDB.12.0;Data Source=D:\test.xlsx;Extended Properties='Excel 12.0 Xml;HDR=YES';

(Hope it works!! If it does not, then there are many more.)

Then u need to use OledbConnection and similar classes for connectivity.

The table name will be the Sheet name with '$' sign at end.

For e.g. to select all rows from "Sheet1", query will be:

SQL

select * from [Sheet1$]

In similar way, to update:

SQL

update [Sheet1$] set Name = 'abc',Age = 15 where Id = 1

try this type of code and believe it will definately work. Works fine for me.

Happy coding.... :)