Develop Reference

C# Error: Microsoft Excel cannot access the file '...'. There are several possible reasons

I've developed an ASP.Net MVC application, that is running on a IIS sever. I've wrote a code that reads a CSV and insert the rows of it in a database.
[HttpPost]
public ActionResult InsertPosition(int id, HttpPostedFileBase position)
{
var posicoesExistentes = db.tbPositions.Where(s => s.id_unique == id).AsEnumerable();
foreach (tbPosition posicao in posicoesExistentes)
{
db.tbPositions.Remove(posicao);
}
if (!Directory.Exists(Server.MapPath("~/App_Data/")))
{
System.IO.Directory.CreateDirectory(Server.MapPath("~/App_Data/"));
}
string excelPath = Server.MapPath("~/App_Data/" + position.FileName);
if (System.IO.File.Exists(excelPath))
{
System.IO.File.Delete(excelPath);
}
position.SaveAs(excelPath);
string tempPath = Server.MapPath("~/App_Data/" + "tmp_" + position.FileName);
System.IO.File.Copy(excelPath, tempPath, true);
Excel.Application application = new Excel.Application();
Excel.Workbook workbook = application.Workbooks.Open(tempPath, ReadOnly: true,Editable:false);
Excel.Worksheet worksheet = workbook.ActiveSheet;
Excel.Range range = worksheet.UsedRange;
application.Visible = true;
for (int row = 1; row < range.Rows.Count - 1; row++)
{
tbPosition p = new tbPosition();
p.position = (((Excel.Range)range.Cells[row, 1]).Text == "") ? null : Convert.ToInt32(((Excel.Range)range.Cells[row, 1]).Text);
p.left = ((Excel.Range)range.Cells[row, 2]).Text;
p.right = ((Excel.Range)range.Cells[row, 3]).Text;
p.paper = ((Excel.Range)range.Cells[row, 4]).Text;
p.denomination = ((Excel.Range)range.Cells[row, 5]).Text;
p.material = ((Excel.Range)range.Cells[row, 6]).Text;
p.norme = ((Excel.Range)range.Cells[row, 7]).Text;
p.finalized_measures = ((Excel.Range)range.Cells[row, 8]).Text;
p.observation = ((Excel.Range)range.Cells[row, 9]).Text;
p.id_unique = id;
db.tbPositions.Add(p);
db.SaveChanges();
}
workbook.Close(true, Type.Missing, Type.Missing);
application.Quit();
System.IO.File.Delete(tempPath);
return Json("Success", JsonRequestBehavior.AllowGet);
}
but in return I got the error ' Microsoft Excel cannot access the file '...'. There are several possible reasons' when I try to open the requested excel file.
I've already tried to open the file as readonly, I've already tried to give permissions to the specifieds folders, multiples ways of close the excel file, and create an copy file of the original and read him. But unsuccessful in each one of these solutions. What have I missed here?

Unsupported
The short answer is that trying to programatically manipulate an Excel document using the Automation API is not supported outside of a UI context. You will come across all sorts of frustrations (for example, the API is permitted to show dialogs - how are you going to click on "OK" if it's running on a web-server?).
Microsoft explicitly state this here
Microsoft does not recommend or support server-side Automation of Office.
So what do I use?
I would recommend using the OpenXML SDK - this is free, fully supported and much faster than the Automation API.
Aspose also has a set of products, but they are not free, and I've not used them.
But I HAVE to do it this way
However, if you absolutely have to use the COM API then the following might help you:
HERE BE DRAGONS
The big problem with automation in Excel is that you need to ensure you close every single reference whenever you use them (by calling ReleaseComObject on it).
For example, the following code will cause Excel to stay open:
var range;
range = excelApplication.Range("A1");
range = excelApplication.Range("A2");
System.Runtime.InteropServices.Marshal.ReleaseComObject(range)
range = Nothing
This is because there is still a reference left over from the call to get range "A1".
Therefore, I would recommend writing a wrapper around the Excel class so that any access to, e.g., a range frees any previous ranges accessed before accessing the new range.
For reference, here is the code I used to release COM objects in the class I wrote:
Private Sub ReleaseComObject(ByVal o As Object)
Try
If Not IsNothing(o) Then
While System.Runtime.InteropServices.Marshal.ReleaseComObject(o) > 0
'Wait for COM object to be released.'
End While
End If
o = Nothing
Catch exc As System.Runtime.InteropServices.COMException
LogError(exc) ' Suppress errors thrown here '
End Try
End Sub

Try this
protected void ImportCSV(object sender, EventArgs e)
{
importbtn();
}
public class Item
{
public Item(string line)
{
var split = line.Split(',');
string FIELD1 = split[0];
string FIELD2 = split[1];
string FIELD3 = split[2];
string mainconn = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
using (SqlConnection con = new SqlConnection(mainconn))
{
using (SqlCommand cmd = new SqlCommand("storedProcedureName", con))
{
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.AddWithValue("#FIELD1", SqlDbType.VarChar).Value = FIELD1;
cmd.Parameters.AddWithValue("#FIELD2", SqlDbType.VarChar).Value = FIELD2;
cmd.Parameters.AddWithValue("#FIELD3", SqlDbType.VarChar).Value = FIELD3;
con.Open();
cmd.ExecuteNonQuery();
}
}
}
}
private void importbtn()
{
try
{
string csvPath = Server.MapPath("~/Files/") + Path.GetFileName(FileUpload1.PostedFile.FileName);
FileUpload1.SaveAs(csvPath);
var listOfObjects = File.ReadLines(csvPath).Select(line => new Item(line)).ToList();
DataTable dt = new DataTable();
dt.Columns.AddRange(new DataColumn[3] { new DataColumn("FIELD1", typeof(string)),
new DataColumn("FIELD2", typeof(string)),
new DataColumn("FIELD3",typeof(string)) });
string csvData = File.ReadAllText(csvPath);
foreach (string row in csvData.Split('\n'))
{
if (!string.IsNullOrEmpty(row))
{
dt.Rows.Add();
int i = 0;
//Execute a loop over the columns.
foreach (string cell in row.Split(','))
{
dt.Rows[dt.Rows.Count - 1][i] = cell;
i++;
}
}
}
GridView1.DataSource = dt;
GridView1.DataBind();
Label1.Text = "File Attached Successfully";
}
catch (Exception ex)
{
Message.Text = "Please Attach any File" /*+ ex.Message*/;
}
}

Preserve empty Excel cells when reading data from clipboard into DataTable

I am using the following code to read Excel data from the clipboard into a C# data table. The code is relatively unchanged as found from this answer to this question. I then add the data table as a data source to a DataGridView control for manipulation.
However, in my Excel data, I have blank/empty cells that I need to preserve, which this code does not do (blank cells are skipped over, effectively compressing each row leaving no empty space; the empty cells are missing from the Excel XML). How could I preserve empty cells when transferring to the data table?
Method:
private DataTable ParseClipboardData(bool blnFirstRowHasHeader)
{
var clipboard = Clipboard.GetDataObject();
if (!clipboard.GetDataPresent("XML Spreadsheet")) return null;
StreamReader streamReader = new StreamReader((MemoryStream)clipboard.GetData("XML Spreadsheet"));
streamReader.BaseStream.SetLength(streamReader.BaseStream.Length - 1);
XmlDocument xmlDocument = new XmlDocument();
xmlDocument.LoadXml(streamReader.ReadToEnd());
XNamespace ssNs = "urn:schemas-microsoft-com:office:spreadsheet";
DataTable dt = new DataTable();
var linqRows = xmlDocument.fwToXDocument().Descendants(ssNs + "Row").ToList<XElement>();
for (int x = 0; x < linqRows.Max(a => a.Descendants(ssNs + "Cell").Count()); x++)
dt.Columns.Add("Column " + x.ToString());
int intCol = 0;
DataRow currentRow;
linqRows.ForEach(rowElement =>
{
intCol = 0;
currentRow = dt.Rows.Add();
rowElement.Descendants(ssNs + "Cell")
.ToList<XElement>()
.ForEach(cell => currentRow[intCol++] = cell.Value);
});
if (blnFirstRowHasHeader)
{
int x = 0;
foreach (DataColumn dcCurrent in dt.Columns)
dcCurrent.ColumnName = dt.Rows[0][x++].ToString();
dt.Rows.RemoveAt(0);
}
return dt;
}
Extension method:
public static XDocument fwToXDocument(this XmlDocument xmlDocument)
{
using (XmlNodeReader xmlNodeReader = new XmlNodeReader(xmlDocument))
{
xmlNodeReader.MoveToContent();
var doc = XDocument.Load(xmlNodeReader);
return doc;
}
}
Contrived example to illustrate: (Excel 2015)
Range in Excel, copied to clipboard
DataGridView on Winform, with data table as data source

The cell's xml will have an Index attribute if the previous cell was missing (had an empty value). You can update your code to check if the column index has changed before copying it to your data table row.
linqRows.ForEach(rowElement =>
{
intCol = 0;
currentRow = dt.Rows.Add();
rowElement.Descendants(ssNs + "Cell")
.ToList<XElement>()
.ForEach(cell =>
{
int cellIndex = 0;
XAttribute indexAttribute = cell.Attribute(ssNs + "Index");
if (indexAttribute != null)
{
Int32.TryParse(indexAttribute.Value, out cellIndex);
intCol = cellIndex - 1;
}
currentRow[intCol] = cell.Value;
intCol++;
});
});

User input to change column header text in DataGrid

I am creating a DataGrid by importing an excel file. I want users manually to be able to change column names from the application.
Edit: Workaround at the bottom
My desktop app will have below logic:
Load excel file and display table in DataGrid
Manually change Column names to match fixed text. (e.x. Column "PricesZZZ" renamed to "Prices", "LeadTimeXXX to "LeadTime")
Export DataGrid to new excel template with only relevant columns that are matched by fixed text (thus the need to have correct
names).
Excel file can have multiple columns and only several of those columns have relevant information and the only way to identify them is to match header name or some other way have user "tell" program which column holds which information.
I need to find a way to change Column name based on user input as I think it's most straightforward. I'm new to c# so sorry if my thinking is a little backwards.
Below is the code snippet I have so far. Might not be relevant for this specific problem, but may help visualize. I use EPPlus library
Import excel
private void btnOpenXL_Click(object sender, RoutedEventArgs e)
{
// Create OpenFileDialog
Microsoft.Win32.OpenFileDialog dlg = new Microsoft.Win32.OpenFileDialog();
// Set filter for file extension and default file extension
dlg.DefaultExt = ".xls";
dlg.Filter = "Excel Files|*.xlsx;*.xls;*.xlsm;*.csv";
// Display OpenFileDialog by calling ShowDialog method
Nullable<bool> result = dlg.ShowDialog();
// Get the selected file name
if (result == true)
{
// Open document
string filename = dlg.FileName;
//call another class to draw the table
dataGrid.ItemsSource = GetDataTableFromExcel(filename).DefaultView;
MessageBox.Show("import done");
}
}
public static DataTable GetDataTableFromExcel(string path, bool hasHeader = true)
{
using (var pck = new OfficeOpenXml.ExcelPackage())
{
using (var stream = File.OpenRead(path))
{
pck.Load(stream);
}
var ws = pck.Workbook.Worksheets.First();
DataTable tbl = new DataTable();
foreach (var firstRowCell in ws.Cells[1, 1, 1, ws.Dimension.End.Column])
{
tbl.Columns.Add(hasHeader ? firstRowCell.Text : string.Format("Column {0}", firstRowCell.Start.Column));
}
var startRow = hasHeader ? 2 : 1;
for (int rowNum = startRow; rowNum <= ws.Dimension.End.Row; rowNum++)
{
var wsRow = ws.Cells[rowNum, 1, rowNum, ws.Dimension.End.Column];
DataRow row = tbl.Rows.Add();
foreach (var cell in wsRow)
{
row[cell.Start.Column - 1] = cell.Text;
}
}
return tbl;
}
}
Export excel
private void btnExportToXL_Click(object sender, RoutedEventArgs e)
{
DataTable dataTable = new DataTable();
dataTable = ((DataView)dataGrid.ItemsSource).ToTable();
ExportDataTableToExcel(dataTable);
MessageBox.Show("export done");
}
public void ExportDataTableToExcel(DataTable dataTable)
{
string path = "C:\\test";
var newFile = new FileInfo(path + "\\" +
DateTime.Now.Ticks + ".xlsx");
using (ExcelPackage pck = new ExcelPackage(newFile))
{
ExcelWorksheet ws = pck.Workbook.Worksheets.Add("Sheet1");
ws.Cells["A1"].LoadFromDataTable(dataTable, true);
pck.Save();
System.Diagnostics.Process.Start(newFile.ToString());
}
}
EDIT:
Workaround by double clicking on any cell in datagrid:
private void dataGrid_MouseDoubleClick(object sender, RoutedEventArgs e)
{
if (dataGrid.SelectedIndex == -1) //if column selected, cant use .CurrentColumn property
{
MessageBox.Show("Please double click on a row");
}
else
{
DataGridColumn columnHeader = dataGrid.CurrentColumn;
if (columnHeader != null)
{
string input = Interaction.InputBox("Title", "Prompt", "Default", 0, 0);
columnHeader.Header = input;
}
}
}

You can change the column names of the datagridview. But note, that this change is limited only to the grid and not it's data source. So in a nutshell, for simple representational purposes, you can use the following code:
dataGrid.Columns[i].HeaderText = "New Column Name"; //i is the index of the column
You can call this code form a Button click event of a Text change event of the input where the user provides the header name. Additionally, if you have the column names beforehand, you can replace then column headers with new values right after the data source has been bound to the grid. Change the headers after this line:
dataGrid.ItemsSource = GetDataTableFromExcel(filename).DefaultView;
//Set new column names here

How to read excel file in asp.net

I am using Epplus library in order to upload data from excel file.The code i am using is perfectly works for excel file which has standard form.ie if first row is column and rest all data corresponds to column.But now a days i am getting regularly , excel files which has different structure and i am not able to read
excel file like as shown below
what i want is on third row i wan only Region and Location Id and its values.Then 7th row is columns and 8th to 15 are its values.Finally 17th row is columns for 18th to 20th .How to load all these datas to seperate datatables
code i used is as shown below
I created an extension method
public static DataSet Exceltotable(this string path)
{
DataSet ds = null;
using (var pck = new OfficeOpenXml.ExcelPackage())
{
try
{
using (var stream = File.Open(path, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
{
pck.Load(stream);
}
ds = new DataSet();
var wss = pck.Workbook.Worksheets;
////////////////////////////////////
//Application app = new Application();
//app.Visible = true;
//app.Workbooks.Add("");
//app.Workbooks.Add(#"c:\MyWork\WorkBook1.xls");
//app.Workbooks.Add(#"c:\MyWork\WorkBook2.xls");
//for (int i = 2; i <= app.Workbooks.Count; i++)
//{
// for (int j = 1; j <= app.Workbooks[i].Worksheets.Count; j++)
// {
// Worksheet ws = app.Workbooks[i].Worksheets[j];
// ws.Copy(app.Workbooks[1].Worksheets[1]);
// }
//}
///////////////////////////////////////////////////
//for(int s=0;s<5;s++)
//{
foreach (var ws in wss)
{
System.Data.DataTable tbl = new System.Data.DataTable();
bool hasHeader = true; // adjust it accordingly( i've mentioned that this is a simple approach)
string ErrorMessage = string.Empty;
foreach (var firstRowCell in ws.Cells[1, 1, 1, ws.Dimension.End.Column])
{
tbl.Columns.Add(hasHeader ? firstRowCell.Text : string.Format("Column {0}", firstRowCell.Start.Column));
}
var startRow = hasHeader ? 2 : 1;
for (var rowNum = startRow; rowNum <= ws.Dimension.End.Row; rowNum++)
{
var wsRow = ws.Cells[rowNum, 1, rowNum, ws.Dimension.End.Column];
var row = tbl.NewRow();
foreach (var cell in wsRow)
{
//modifed by faras
if (cell.Text != null)
{
row[cell.Start.Column - 1] = cell.Text;
}
}
tbl.Rows.Add(row);
tbl.TableName = ws.Name;
}
DataTable dt = RemoveEmptyRows(tbl);
ds.Tables.Add(dt);
}
}
catch (Exception exp)
{
}
return ds;
}
}

If you're providing the template for users to upload, you can mitigate this some by using named ranges in your spreadsheet. That's a good idea anyway when programmatically working with Excel because it helps when you modify your own spreadsheet, not just when the user does.
You probably know how to name a range, but for the sake of completeness, here's how to name a range.
When you're working with the spreadsheet in code you can get a reference to the range using [yourworkbook].Names["yourNamedRange"]. If it's just a single cell and you need to reference the row or column index you can use .Start.Row or .Start.Column.
I add named ranges for anything - cells containing particular values, columns, header rows, rows where sets of data begin. If I need row or column indexes I assign useful variable names. That protects you from having all sorts of "magic numbers" in your spreadsheet. You (or your users) can move quite a bit around without breaking anything.
If they modify the structure too much then it won't work. You can also use protection on the workbook and worksheet to ensure that they can't accidentally modify the structure - tabs, rows, columns.
This is loosely taken from a test I was working with last weekend when I was learning this. It was just a "hello world" so I wasn't trying to make it all streamlined and perfect. (I was working on populating a spreadsheet, not reading one, so I'm just learning the properties as I go.)
// Open the workbook
using (var package = new ExcelPackage(new FileInfo("PriceQuoteTemplate.xlsx")))
{
// Get the worksheet I'm looking for
var quoteSheet = package.Workbook.Worksheets["Quote"];
//If I wanted to get the text from one named range
var cellText = quoteSheet.Workbook.Names["myNamedRange"].Text
//If I wanted to get the cell's value as some other type
var cellValue = quoteSheet.Workbook.Names["myNamedRange"].GetValue<int>();
//If I had a named range and I wanted to loop through the rows and get
//values from certain columns
var myRange = quoteSheet.Workbook.Names["rangeContainingRows"];
//This is a named range used to mark a column. So instead of using a
//magic number, I'll read from whatever column has this named range.
var someColumn = quoteSheet.Workbook.Names["columnLabel"].Start.Column;
for(var rowNumber = myRange.Start.Row; rowNumber < myRange.Start.Row + myRange.Rows; rowNumber++)
{
var getTheTextForTheRowAndColumn = quoteSheet.Cells(rowNumber, someColumn).Text
}
There might be a more elegant way to go about it. I just started using this myself. But the idea is you tell it to find a certain named range on the spreadsheet, and then you use the row or column number of that range instead of a magic row or column number.
Even though a range might be one cell, one row, or one column, it can potentially be a larger area. That's why I use .Start.Row. In other words, give me the row for the first cell in the range. If a range has more than one row, the .Rows property indicates the number of rows so I know how many there are. That means someone could even insert rows without breaking the code.

using System;
using System.Collections.Generic;
using System.Data;
using System.Data.OleDb;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.IO;
namespace ReadData
{
public partial class ImportExelDataInGridView : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void btnUpload_Click(object sender, EventArgs e)
{
//Coneection String by default empty
string ConStr = "";
//Extantion of the file upload control saving into ext because
//there are two types of extation .xls and .xlsx of excel
string ext = Path.GetExtension(FileUpload1.FileName).ToLower();
//getting the path of the file
string path = Server.MapPath("~/MyFolder/"+FileUpload1.FileName);
//saving the file inside the MyFolder of the server
FileUpload1.SaveAs(path);
Label1.Text = FileUpload1.FileName + "\'s Data showing into the GridView";
//checking that extantion is .xls or .xlsx
if (ext.Trim() == ".xls")
{
//connection string for that file which extantion is .xls
ConStr = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + path + ";Extended Properties=\"Excel 8.0;HDR=Yes;IMEX=2\"";
}
else if (ext.Trim() == ".xlsx")
{
//connection string for that file which extantion is .xlsx
ConStr = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + path + ";Extended Properties=\"Excel 12.0;HDR=Yes;IMEX=2\"";
}
//making query
string query = "SELECT * FROM [Sheet1$]";
//Providing connection
OleDbConnection conn = new OleDbConnection(ConStr);
//checking that connection state is closed or not if closed the
//open the connection
if (conn.State == ConnectionState.Closed)
{
conn.Open();
}
//create command object
OleDbCommand cmd = new OleDbCommand(query, conn);
// create a data adapter and get the data into dataadapter
OleDbDataAdapter da = new OleDbDataAdapter(cmd);
DataSet ds = new DataSet();
//fill the excel data to data set
da.Fill(ds);
if (ds.Tables != null && ds.Tables.Count > 0)
{
for (int i = 0; i < ds.Tables[0].Columns.Count; i++)
{
if (ds.Tables[0].Columns[0].ToString() == "ID" && ds.Tables[0].Columns[1].ToString() == "name")
{
}
//else if (ds.Tables[0].Rows[0][i].ToString().ToUpper() == "NAME")
//{
//}
//else if (ds.Tables[0].Rows[0][i].ToString().ToUpper() == "EMAIL")
//{
//}
}
}
//set data source of the grid view
gvExcelFile.DataSource = ds.Tables[0];
//binding the gridview
gvExcelFile.DataBind();
//close the connection
conn.Close();
}
}
}

try
{
System.Diagnostics.Process[] process = System.Diagnostics.Process.GetProcessesByName("Excel");
foreach (System.Diagnostics.Process p in process)
{
if (!string.IsNullOrEmpty(p.ProcessName))
{
try
{
p.Kill();
}
catch { }
}
}
REF_User oREF_User = new REF_User();
oREF_User = (REF_User)Session["LoggedUser"];
string pdfFilePath = Server.MapPath("~/FileUpload/" + oREF_User.USER_ID + "");
if (Directory.Exists(pdfFilePath))
{
System.IO.DirectoryInfo di = new DirectoryInfo(pdfFilePath);
foreach (FileInfo file in di.GetFiles())
{
file.Delete();
}
Directory.Delete(pdfFilePath);
}
Directory.CreateDirectory(pdfFilePath);
string path = Server.MapPath("~/FileUpload/" + oREF_User.USER_ID + "/");
if (Path.GetExtension(FileUpload1.FileName) == ".xlsx")
{
string fullpath1 = path + Path.GetFileName(FileUpload1.FileName);
if (FileUpload1.FileName != "")
{
FileUpload1.SaveAs(fullpath1);
}
FileStream Stream = new FileStream(fullpath1, FileMode.Open);
IExcelDataReader ExcelReader = ExcelReaderFactory.CreateOpenXmlReader(Stream);
DataSet oDataSet = ExcelReader.AsDataSet();
Stream.Close();
bool result = false;
foreach (System.Data.DataTable oDataTable in oDataSet.Tables)
{
//ToDO code
}
oBL_PlantTransactions.InsertList(oListREF_PlantTransactions, null);
ShowMessage("Successfully saved!", REF_ENUM.MessageType.Success);
}
else
{
ShowMessage("File Format Incorrect", REF_ENUM.MessageType.Error);
}
}
catch (Exception ex)
{
ShowMessage("Please check the details and submit again!", REF_ENUM.MessageType.Error);
System.Diagnostics.Process[] process = System.Diagnostics.Process.GetProcessesByName("Excel");
foreach (System.Diagnostics.Process p in process)
{
if (!string.IsNullOrEmpty(p.ProcessName))
{
try
{
p.Kill();
}
catch { }
}
}
}

I found this article to be very helpful.
It lists various libraries you can choose from. One of the libraries I used is EPPlus as shown below.
Nuget: EPPlus Library
Excel Sheet 1 Data
Cell A2 Value :
Cell A2 Color :
Cell B2 Formula :
Cell B2 Value :
Cell B2 Border :
Excel Sheet 2 Data
Cell A2 Formula :
Cell A2 Value :
static void Main(string[] args)
{
using(var package = new ExcelPackage(new FileInfo("Book.xlsx")))
{
var firstSheet = package.Workbook.Worksheets["First Sheet"];
Console.WriteLine("Sheet 1 Data");
Console.WriteLine($"Cell A2 Value : {firstSheet.Cells["A2"].Text}");
Console.WriteLine($"Cell A2 Color : {firstSheet.Cells["A2"].Style.Font.Color.LookupColor()}");
Console.WriteLine($"Cell B2 Formula : {firstSheet.Cells["B2"].Formula}");
Console.WriteLine($"Cell B2 Value : {firstSheet.Cells["B2"].Text}");
Console.WriteLine($"Cell B2 Border : {firstSheet.Cells["B2"].Style.Border.Top.Style}");
Console.WriteLine("");
var secondSheet = package.Workbook.Worksheets["Second Sheet"];
Console.WriteLine($"Sheet 2 Data");
Console.WriteLine($"Cell A2 Formula : {secondSheet.Cells["A2"].Formula}");
Console.WriteLine($"Cell A2 Value : {secondSheet.Cells["A2"].Text}");
}
}

export data to excel file in an asp.net application

Can someone provide a link with a tutorial about exporting data to an excel file using c# in an asp.net web application.I searched the internet but I didn't find any tutorials that will explain how they do it.

You can use Interop http://www.c-sharpcorner.com/UploadFile/Globalking/datasettoexcel02272006232336PM/datasettoexcel.aspx
Or if you don't want to install Microsoft Office on a webserver
I recommend using CarlosAg.ExcelXmlWriter which can be found here: http://www.carlosag.net/tools/excelxmlwriter/
code sample for ExcelXmlWriter:
using CarlosAg.ExcelXmlWriter;
class TestApp {
static void Main(string[] args) {
Workbook book = new Workbook();
Worksheet sheet = book.Worksheets.Add("Sample");
WorksheetRow row = sheet.Table.Rows.Add();
row.Cells.Add("Hello World");
book.Save(#"c:\test.xls");
}
}

There is a easy way to use npoi.mapper with just below 2 lines
var mapper = new Mapper();
mapper.Save("test.xlsx", objects, "newSheet");

Pass List to below method, that will convert the list to buffer and then return buffer, a file will be downloaded.
List<T> resultList = New List<T>();
byte[] buffer = Write(resultList, true, "AttendenceSummary");
return File(buffer, "application/excel", reportTitle + ".xlsx");
public static byte[] Write<T>(IEnumerable<T> list, bool xlsxExtension = true, string sheetName = "ExportData")
{
if (list == null)
{
throw new ArgumentNullException("list");
}
XSSFWorkbook hssfworkbook = new XSSFWorkbook();
int Rowspersheet = 15000;
int TotalRows = list.Count();
int TotalSheets = TotalRows / Rowspersheet;
for (int i = 0; i <= TotalSheets; i++)
{
ISheet sheet1 = hssfworkbook.CreateSheet(sheetName + "_" + i);
IRow row = sheet1.CreateRow(0);
int index = 0;
foreach (PropertyInfo property in typeof(T).GetProperties())
{
ICellStyle cellStyle = hssfworkbook.CreateCellStyle();
IFont cellFont = hssfworkbook.CreateFont();
cellFont.Boldweight = (short)NPOI.SS.UserModel.FontBoldWeight.Bold;
cellStyle.SetFont(cellFont);
ICell cell = row.CreateCell(index++);
cell.CellStyle = cellStyle;
cell.SetCellValue(property.Name);
}
int rowIndex = 1;
// int rowIndex2 = 1;
foreach (T obj in list.Skip(Rowspersheet * i).Take(Rowspersheet))
{
row = sheet1.CreateRow(rowIndex++);
index = 0;
foreach (PropertyInfo property in typeof(T).GetProperties())
{
ICell cell = row.CreateCell(index++);
cell.SetCellValue(Convert.ToString(property.GetValue(obj)));
}
}
}
MemoryStream file = new MemoryStream();
hssfworkbook.Write(file);
return file.ToArray();
}

You can try the following links :
http://www.codeproject.com/Articles/164582/8-Solutions-to-Export-Data-to-Excel-for-ASP-NET
Export data as Excel file from ASP.NET
http://codeissue.com/issues/i14e20993075634/how-to-export-gridview-control-data-to-excel-file-using-asp-net

I've written a C# class, which lets you write your DataSet, DataTable or List<> data directly into a Excel .xlsx file using the OpenXML libraries.
http://mikesknowledgebase.com/pages/CSharp/ExportToExcel.htm
It's completely free to download, and very ASP.Net friendly.
Just pass my C# function the data to be written, the name of the file you want to create, and your page's "Response" variable, and it'll create the Excel file for you, and write it straight to the Page, ready for the user to Save/Open.
class Employee;
List<Employee> listOfEmployees = new List<Employee>();
// The following ASP.Net code gets run when I click on my "Export to Excel" button.
protected void btnExportToExcel_Click(object sender, EventArgs e)
{
// It doesn't get much easier than this...
CreateExcelFile.CreateExcelDocument(listOfEmployees, "Employees.xlsx", Response);
}
(I work for a finanical company, and we'd be lost without this functionality in every one of our apps !!)