Exporting from gridview to excel is not showing long numbers - excel

Question

Hello I'm trying to export my data from a gridview to excel the problem is I have a nvarchar column the have the following barcode: 00373228210001695726 and in excel after export it looks like this 3,73228E+17
my query looks like this:
DataTable dt = new DataTable();
SqlConnection connection = new SqlConnection("Data Source=AP;Initial Catalog=MGW;User Id=sa;Password=GaUbdFO2;App=EntityFramework;");
try
{
connection.Open();
string sqlStatement = " ";
sqlStatement += " SELECT UserName AS UserID, Site, AddressID, Parameters, Content AS Barcode , TriggerDate, ReceivedDate, Action, DeviceID, Longitude, Latitude, CASE WHEN Latitude != '' THEN 'View Map Location' Else 'No Location' END AS LatitudeMSG FROM RequestWithLocation WHERE";
sqlStatement += " Content = #Content ";
if (!string.IsNullOrWhiteSpace(TextBoxStart.Text) && !string.IsNullOrWhiteSpace(TextBoxEnd.Text))
{
sqlStatement += " AND TriggerDate >= #TriggerDateStart AND TriggerDate <= #TriggerDateEnd ";
}
sqlStatement += " ORDER BY TriggerDate DESC";
using (SqlCommand sqlCmd = new SqlCommand(sqlStatement, connection))
{
sqlCmd.Parameters.AddWithValue("#Content", TextBoxSearch.Text);
if (!string.IsNullOrWhiteSpace(TextBoxStart.Text) && !string.IsNullOrWhiteSpace(TextBoxEnd.Text))
{
sqlCmd.Parameters.AddWithValue("#TriggerDateStart", Convert.ToDateTime(TextBoxStart.Text));
sqlCmd.Parameters.AddWithValue("#TriggerDateEnd", Convert.ToDateTime(TextBoxEnd.Text).AddDays(+1));
}
using (SqlDataAdapter sqlDa = new SqlDataAdapter(sqlCmd))
{
sqlDa.Fill(dt);
if (dt.Rows.Count > 0)
{
GridDisplayData.DataSource = dt;
GridDisplayData.DataBind();
lblError.Text = "";
}
else
{
Page.ClientScript.RegisterStartupScript(GetType(), "msgbox", "alert('No data found');", true);
}
}
}
}
catch (Exception)
{
Page.ClientScript.RegisterStartupScript(GetType(), "msgbox", "alert('Search timed-out! try again..');", true);
}
EXPORT FUNCTION
protected void btnExportToExcel_Click(object sender, EventArgs e)
{
Response.Clear();
Response.AddHeader("content-disposition", "attachchment; filename=Report_EventScan.xls; IMEX=1;");
Response.Charset = "";
Response.ContentType = "application/vnd.xls";
StringWriter sw = new StringWriter();
HtmlTextWriter hw = new HtmlTextWriter(sw);
GridDisplayData.RenderControl(hw);
//Panel7.RenderControl(hw);
Response.Write(sw.ToString());
Response.End();
}

Answer 1

Use Response.Write("'" + sw.ToString()); to force a prefixed single quotation character in front of the number. That forces Excel to adopt text formatting.
(I'm assuming that + is a string concatenation in your language; it might be &).

Answer 2

I solved my problem. this is what I did:
You can download the EPPlus Excel reader from here http://epplus.codeplex.com/
Then using OfficeOpenXml; on top of your project and the following code to your export button, this should work for everyone who use a DataSet which is saved in a ViewState
protected void btnExportToExcel_Click(object sender, EventArgs e)
{
DataSet dt = new DataSet();
dt = (DataSet)ViewState["QueryTable"];
MemoryStream ms = new MemoryStream();
int i = 1;
using (ExcelPackage package = new ExcelPackage(ms))
{
foreach (DataTable table in dt.Tables)
{
ExcelWorksheet worksheet = package.Workbook.Worksheets.Add("My Excel Report " + i++);
worksheet.Cells["A1"].LoadFromDataTable(table, true);
}
Response.Clear();
package.SaveAs(Response.OutputStream);
Response.AddHeader("content-disposition", "attachchment; filename= test.xls");
Response.Charset = "";
Response.ContentType = "application/vnd.xls";
Response.End();
}
}