The solution to read excel by using C#

The solution to read excel by using C# - c#

Situation:
I'm using C#, and I need to read the content from an excel file.
The content in the excel file will be looks alike as the image.
The first column is the criteria, and the second column is the amount of the criteria. These content will have more than 1000 rows and will be placed at the last sheet of the excel file.
I'm trying to use File Helper to read the content from excel.
But from the example provided, I only know that I can read text file but not excel file.
Questions:
Is there any better example to show me how to read the content from excel by using the FileHelpers?
Is there any other better solution with example that can help me to read the content from excel. Please direct me.

You could ExcelToEnumerable for this. Here's an example:
First define a class that represents a row of spreadsheet data. In your case, it might be something like:
public class SpreadsheetRow
{
public string Category { get; set; }
public int Frequency { get; set; }
}
Then use ExcelToEnumerable to convert the spreadsheet data into an IEnumerable of type SpreadsheetRow
var filePath = "../Path/To/Spreadsheet.xlsx";
IEnumerable<SpreadsheetRow> result = filePath.ExcelToEnumerable<SpreadsheetRow>(x => x.UsingHeaderNames(false)
.Property(y => y.Category).UsesColumnNumber(0)
.Property(y => y.Frequency).UsesColumnNumber(1));
Disclaimer: I'm the author of ExcelToEnumerable

I think you should use OpenXML which will give you excel data in Datatable format and later you can use as per your wish.
static void Main(string[] args)
{
DataTable dt = new DataTable();
using (SpreadsheetDocument spreadSheetDocument = SpreadsheetDocument.Open(#"..\..\example.xlsx", false))
{
WorkbookPart workbookPart = spreadSheetDocument.WorkbookPart;
IEnumerable<Sheet> sheets = spreadSheetDocument.WorkbookPart.Workbook.GetFirstChild<Sheets>().Elements<Sheet>();
string relationshipId = sheets.First().Id.Value;
WorksheetPart worksheetPart = (WorksheetPart)spreadSheetDocument.WorkbookPart.GetPartById(relationshipId);
Worksheet workSheet = worksheetPart.Worksheet;
SheetData sheetData = workSheet.GetFirstChild<SheetData>();
IEnumerable<Row> rows = sheetData.Descendants<Row>();
foreach (Cell cell in rows.ElementAt(0))
{
dt.Columns.Add(GetCellValue(spreadSheetDocument, cell));
}
foreach (Row row in rows) //this will also include your header row...
{
DataRow tempRow = dt.NewRow();
for (int i = 0; i < row.Descendants<Cell>().Count(); i++)
{
tempRow[i] = GetCellValue(spreadSheetDocument, row.Descendants<Cell>().ElementAt(i-1));
}
dt.Rows.Add(tempRow);
}
}
dt.Rows.RemoveAt(0); //...so i'm taking it out here.
}
public static string GetCellValue(SpreadsheetDocument document, Cell cell)
{
SharedStringTablePart stringTablePart = document.WorkbookPart.SharedStringTablePart;
string value = cell.CellValue.InnerXml;
if (cell.DataType != null && cell.DataType.Value == CellValues.SharedString)
{
return stringTablePart.SharedStringTable.ChildElements[Int32.Parse(value)].InnerText;
}
else
{
return value;
}
}
Note: Reference From Excel to DataTable in C# with Open XML

You can read an Excel by using Microsoft.Office.Interop.Excel Library . You can find the full process in attached link
How to read from Excel in C#
using System;
using System.Windows.Forms;
using Excel = Microsoft.Office.Interop.Excel;
namespace WindowsApplication1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
Excel.Application xlApp ;
Excel.Workbook xlWorkBook ;
Excel.Worksheet xlWorkSheet ;
Excel.Range range ;
string str;
int rCnt = 0;
int cCnt = 0;
xlApp = new Excel.Application();
xlWorkBook = xlApp.Workbooks.Open("csharp.net-informations.xls", 0, true, 5, "", "", true, Microsoft.Office.Interop.Excel.XlPlatform.xlWindows, "\t", false, false, 0, true, 1, 0);
xlWorkSheet = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(1);
range = xlWorkSheet.UsedRange;
for (rCnt = 1; rCnt <= range.Rows.Count; rCnt++)
{
for (cCnt = 1; cCnt <= range.Columns.Count; cCnt++)
{
str = (string)(range.Cells[rCnt, cCnt] as Excel.Range).Value2 ;
MessageBox.Show(str);
}
}
xlWorkBook.Close(true, null, null);
xlApp.Quit();
releaseObject(xlWorkSheet);
releaseObject(xlWorkBook);
releaseObject(xlApp);
}
private void releaseObject(object obj)
{
try
{
System.Runtime.InteropServices.Marshal.ReleaseComObject(obj);
obj = null;
}
catch (Exception ex)
{
obj = null;
MessageBox.Show("Unable to release the Object " + ex.ToString());
}
finally
{
GC.Collect();
}
}
}
}

Related

Quickly read data from Excel

I have the code below reading data from an Excel worksheet and converting it to a pipe delimited text file. It works. The problem is it's quite slow as I have to read 1 cell at a time in order to add in the pipe.
I wondered if there was a better way to do this i.e. read the data into memory/array in one step and act on it there.
public string Process(string filename)
{
Excel.Application xlApp;
Excel.Workbook xlWorkBook;
Excel.Worksheet xlWorkSheet;
Excel.Range range;
string str = "";
int rCnt = 0;
int cCnt = 0;
object misValue = System.Reflection.Missing.Value;
xlApp = new Excel.Application();
xlWorkBook = xlApp.Workbooks.Open(filename, 0, true, 5, "", "", true, Microsoft.Office.Interop.Excel.XlPlatform.xlWindows, "\t", false, false, 0, true, 1, 0);
xlWorkSheet = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(1); //Use the 1st worksheet
StreamWriter sw = new StreamWriter(destpath);
range = xlWorkSheet.UsedRange;
for (rCnt = 1; rCnt <= range.Rows.Count; rCnt++)
{
if ((rCnt % 1000) == 0)
{
txtProgress.Text = "Rows processed: "+ rCnt;
}
for (cCnt = 1; cCnt <= range.Columns.Count; cCnt++)
{
str = str + ToStr((range.Cells[rCnt, cCnt] as Excel.Range).Value2) + "|";
}
sw.WriteLine(str);
str = "";
}
xlWorkBook.Close(true, null, null);
xlApp.Quit();
sw.Close();
releaseObject(xlWorkSheet);
releaseObject(xlWorkBook);
releaseObject(xlApp);
MessageBox.Show("Complete","Status");
return "Success";
}
public static string ToStr(object readField)
{
if ((readField != null))
{
if (readField.GetType() != typeof(System.DBNull))
{
return Convert.ToString(readField);
}
else
{
return "";
}
}
else
{
return "";
}
}
private void releaseObject(object obj)
{
try
{
System.Runtime.InteropServices.Marshal.ReleaseComObject(obj);
obj = null;
}
catch (Exception ex)
{
obj = null;
MessageBox.Show("Unable to release the Object " + ex.ToString());
}
finally
{
GC.Collect();
}
}

If you plan on only performing a read on the excel file content, I suggest you use the ExcelDataReader library Link, which extracts the worksheetData into a DataSet object.
static void Main(string[] args)
{
IExcelDataReader reader = null;
string FilePath = "PathToExcelFile";
//Load file into a stream
FileStream stream = File.Open(FilePath, FileMode.Open, FileAccess.Read);
//Must check file extension to adjust the reader to the excel file type
if (System.IO.Path.GetExtension(FilePath).Equals(".xls"))
{
reader = ExcelReaderFactory.CreateBinaryReader(stream);
}
else if (System.IO.Path.GetExtension(FilePath).Equals(".xlsx"))
{
reader = ExcelReaderFactory.CreateBinaryReader(stream);
}
if (reader != null)
{
//Fill DataSet
System.Data.DataSet result = reader.AsDataSet();
try
{
//Loop through rows for the desired worksheet
//In this case I use the table index "0" to pick the first worksheet in the workbook
foreach (DataRow row in result.Tables[0].Rows)
{
string FirstColumn = row[0].ToString();
}
}
catch
{
}
}
}

you can use LinqToExcel nuget package
https://www.nuget.org/packages/LinqToExcel/1.10.1
sample code:
string path = #"Users.xlsx";
var excel = new ExcelQueryFactory(path);
return (from c in excel.Worksheet<User>()
select c).OrderBy(a => a.Name).ToList();

How to read large excel file in asp.net c# by splitting it into simpler? [duplicate]

How to read an Excel file using C#? I open an Excel file for reading and copy it to clipboard to search email format, but I don't know how to do it.
FileInfo finfo;
Excel.ApplicationClass ExcelObj = new Excel.ApplicationClass();
ExcelObj.Visible = false;
Excel.Workbook theWorkbook;
Excel.Worksheet worksheet;
if (listView1.Items.Count > 0)
{
foreach (ListViewItem s in listView1.Items)
{
finfo = new FileInfo(s.Text);
if (finfo.Extension == ".xls" || finfo.Extension == ".xlsx" || finfo.Extension == ".xlt" || finfo.Extension == ".xlsm" || finfo.Extension == ".csv")
{
theWorkbook = ExcelObj.Workbooks.Open(s.Text, 0, true, 5, "", "", true, Excel.XlPlatform.xlWindows, "\t", false, false, 0, true, false, false);
for (int count = 1; count <= theWorkbook.Sheets.Count; count++)
{
worksheet = (Excel.Worksheet)theWorkbook.Worksheets.get_Item(count);
worksheet.Activate();
worksheet.Visible = false;
worksheet.UsedRange.Cells.Select();
}
}
}
}

OK,
One of the more difficult concepts to grasp about Excel VSTO programming is that you don't refer to cells like an array, Worksheet[0][0] won't give you cell A1, it will error out on you. Even when you type into A1 when Excel is open, you are actually entering data into Range A1. Therefore you refer to cells as Named Ranges. Here's an example:
Excel.Worksheet sheet = workbook.Sheets["Sheet1"] as Excel.Worksheet;
Excel.Range range = sheet.get_Range("A1", Missing.Value)
You can now literally type:
range.Text // this will give you the text the user sees
range.Value2 // this will give you the actual value stored by Excel (without rounding)
If you want to do something like this:
Excel.Range range = sheet.get_Range("A1:A5", Missing.Value)
if (range1 != null)
foreach (Excel.Range r in range1)
{
string user = r.Text
string value = r.Value2
}
There might be a better way, but this has worked for me.
The reason you need to use Value2 and not Value is because the Value property is a parametrized and C# doesn't support them yet.
As for the cleanup code, i will post that when i get to work tomorrow, i don't have the code with me, but it's very boilerplate. You just close and release the objects in the reverse order you created them. You can't use a Using() block because the Excel.Application or Excel.Workbook doesn't implement IDisposable, and if you don't clean-up, you will be left with a hanging Excel objects in memory.
Note:
If you don't set the Visibility property Excel doesn't display, which can be disconcerting to your users, but if you want to just rip the data out, that is probably good enough
You could OleDb, that will work too.
I hope that gets you started, let me know if you need further clarification. I'll post a complete
here is a complete sample:
using System;
using System.IO;
using System.Reflection;
using NUnit.Framework;
using ExcelTools = Ms.Office;
using Excel = Microsoft.Office.Interop.Excel;
namespace Tests
{
[TestFixture]
public class ExcelSingle
{
[Test]
public void ProcessWorkbook()
{
string file = #"C:\Users\Chris\Desktop\TestSheet.xls";
Console.WriteLine(file);
Excel.Application excel = null;
Excel.Workbook wkb = null;
try
{
excel = new Excel.Application();
wkb = ExcelTools.OfficeUtil.OpenBook(excel, file);
Excel.Worksheet sheet = wkb.Sheets["Data"] as Excel.Worksheet;
Excel.Range range = null;
if (sheet != null)
range = sheet.get_Range("A1", Missing.Value);
string A1 = String.Empty;
if( range != null )
A1 = range.Text.ToString();
Console.WriteLine("A1 value: {0}", A1);
}
catch(Exception ex)
{
//if you need to handle stuff
Console.WriteLine(ex.Message);
}
finally
{
if (wkb != null)
ExcelTools.OfficeUtil.ReleaseRCM(wkb);
if (excel != null)
ExcelTools.OfficeUtil.ReleaseRCM(excel);
}
}
}
}
I'll post the functions from ExcelTools tomorrow, I don't have that code with me either.
Edit:
As promised, here are the Functions from ExcelTools you might need.
public static Excel.Workbook OpenBook(Excel.Application excelInstance, string fileName, bool readOnly, bool editable,
bool updateLinks) {
Excel.Workbook book = excelInstance.Workbooks.Open(
fileName, updateLinks, readOnly,
Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing,
Type.Missing, editable, Type.Missing, Type.Missing, Type.Missing,
Type.Missing, Type.Missing);
return book;
}
public static void ReleaseRCM(object o) {
try {
System.Runtime.InteropServices.Marshal.ReleaseComObject(o);
} catch {
} finally {
o = null;
}
}
To be frank, this stuff is much easier if you use VB.NET. It's in C# because I didn't write it. VB.NET does option parameters well, C# does not, hence the Type.Missing. Once you typed Type.Missing twice in a row, you run screaming from the room!
As for you question, you can try to following:
http://msdn.microsoft.com/en-us/library/microsoft.office.interop.excel.range.find(VS.80).aspx
I will post an example when I get back from my meeting... cheers
Edit: Here is an example
range = sheet.Cells.Find("Value to Find",
Type.Missing,
Type.Missing,
Type.Missing,
Type.Missing,
Excel.XlSearchDirection.xlNext,
Type.Missing,
Type.Missing, Type.Missing);
range.Text; //give you the value found
Here is another example inspired by this site:
range = sheet.Cells.Find("Value to find", Type.Missing, Type.Missing,Excel.XlLookAt.xlWhole,Excel.XlSearchOrder.xlByColumns,Excel.XlSearchDirection.xlNext,false, false, Type.Missing);
It helps to understand the parameters.
P.S. I'm one of those weird people who enjoys learning COM automation. All this code steamed from a tool I wrote for work which required me to process over 1000+ spreadsheets from the lab each Monday.

You can use Microsoft.Office.Interop.Excel assembly to process excel files.
Right click on your project and go to Add reference. Add the
Microsoft.Office.Interop.Excel assembly.
Include using
Microsoft.Office.Interop.Excel; to make use of assembly.
Here is the sample code:
using Microsoft.Office.Interop.Excel;
//create the Application object we can use in the member functions.
Microsoft.Office.Interop.Excel.Application _excelApp = new Microsoft.Office.Interop.Excel.Application();
_excelApp.Visible = true;
string fileName = "C:\\sampleExcelFile.xlsx";
//open the workbook
Workbook workbook = _excelApp.Workbooks.Open(fileName,
Type.Missing, Type.Missing, Type.Missing, Type.Missing,
Type.Missing, Type.Missing, Type.Missing, Type.Missing,
Type.Missing, Type.Missing, Type.Missing, Type.Missing,
Type.Missing, Type.Missing);
//select the first sheet
Worksheet worksheet = (Worksheet)workbook.Worksheets[1];
//find the used range in worksheet
Range excelRange = worksheet.UsedRange;
//get an object array of all of the cells in the worksheet (their values)
object[,] valueArray = (object[,])excelRange.get_Value(
XlRangeValueDataType.xlRangeValueDefault);
//access the cells
for (int row = 1; row <= worksheet.UsedRange.Rows.Count; ++row)
{
for (int col = 1; col <= worksheet.UsedRange.Columns.Count; ++col)
{
//access each cell
Debug.Print(valueArray[row, col].ToString());
}
}
//clean up stuffs
workbook.Close(false, Type.Missing, Type.Missing);
Marshal.ReleaseComObject(workbook);
_excelApp.Quit();
Marshal.FinalReleaseComObject(_excelApp);

Why don't you create OleDbConnection? There are a lot of available resources in the Internet. Here is an example
OleDbConnection con = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source="+filename+";Extended Properties=Excel 8.0");
con.Open();
try
{
//Create Dataset and fill with imformation from the Excel Spreadsheet for easier reference
DataSet myDataSet = new DataSet();
OleDbDataAdapter myCommand = new OleDbDataAdapter(" SELECT * FROM ["+listname+"$]" , con);
myCommand.Fill(myDataSet);
con.Close();
richTextBox1.AppendText("\nDataSet Filled");
//Travers through each row in the dataset
foreach (DataRow myDataRow in myDataSet.Tables[0].Rows)
{
//Stores info in Datarow into an array
Object[] cells = myDataRow.ItemArray;
//Traverse through each array and put into object cellContent as type Object
//Using Object as for some reason the Dataset reads some blank value which
//causes a hissy fit when trying to read. By using object I can convert to
//String at a later point.
foreach (object cellContent in cells)
{
//Convert object cellContect into String to read whilst replacing Line Breaks with a defined character
string cellText = cellContent.ToString();
cellText = cellText.Replace("\n", "|");
//Read the string and put into Array of characters chars
richTextBox1.AppendText("\n"+cellText);
}
}
//Thread.Sleep(15000);
}
catch (Exception ex)
{
MessageBox.Show(ex.ToString());
//Thread.Sleep(15000);
}
finally
{
con.Close();
}

try
{
DataTable sheet1 = new DataTable("Excel Sheet");
OleDbConnectionStringBuilder csbuilder = new OleDbConnectionStringBuilder();
csbuilder.Provider = "Microsoft.ACE.OLEDB.12.0";
csbuilder.DataSource = fileLocation;
csbuilder.Add("Extended Properties", "Excel 12.0 Xml;HDR=YES");
string selectSql = #"SELECT * FROM [Sheet1$]";
using (OleDbConnection connection = new OleDbConnection(csbuilder.ConnectionString))
using (OleDbDataAdapter adapter = new OleDbDataAdapter(selectSql, connection))
{
connection.Open();
adapter.Fill(sheet1);
}
}
catch (Exception e)
{
Console.WriteLine(e.Message);
}
This worked for me. Please try it and let me know for queries.

First of all, it's important to know what you mean by "open an Excel file for reading and copy it to clipboard..."
This is very important because there are many ways you could do that depending just on what you intend to do. Let me explain:
If you want to read a set of data and copy that in the clipboard and you know the data format (e.g. column names), I suggest you use an OleDbConnection to open the file, this way you can treat the xls file content as a Database Table, so you can read data with SQL instruction and treat the data as you want.
If you want to do operations on the data with the Excel object model then open it in the way you began.
Some time it's possible to treat an xls file as a kind of csv file, there are tools like File Helpers which permit you to treat and open an xls file in a simple way by mapping a structure on an arbitrary object.
Another important point is in which Excel version the file is.
I have, unfortunately I say, a strong experience working with Office automation in all ways, even if bounded in concepts like Application Automation, Data Management and Plugins, and generally I suggest only as the last resort, to using Excel automation or Office automation to read data; just if there aren't better ways to accomplish that task.
Working with automation could be heavy in performance, in terms of resource cost, could involve in other issues related for example to security and more, and last but not at least, working with COM interop it's not so "free"..
So my suggestion is think and analyze the situation within your needs and then take the better way.

Here's a 2020 answer - if you don't need to support the older .xls format (so pre 2003) you could use either:
LightweightExcelReader to access specfic cells, or cursor through all the data in a spreadsheet.
or
ExcelToEnumerable if you want to map spreadsheet data to a list of objects.
Pros :
Performance - at the time of writing (the the fastest way to read an .xlsx file)[https://github.com/ChrisHodges/ExcelToEnumerable#performance].
Simplicity - less verbose than OLE DB or OpenXml
Cons:
Neither LightweightExcelReader nor ExcelToEnumerable support .xls files.
Disclaimer: I am the author of LightweightExcelReader and ExcelToEnumerable

Use Open XML.
Here is some code to process a spreadsheet with a specific tab or sheet name and dump it to something like CSV. (I chose a pipe instead of comma).
I wish it was easier to get the value from a cell, but I think this is what we are stuck with. You can see that I reference the MSDN documents where I got most of this code. That is what Microsoft recommends.
/// <summary>
/// Got code from: https://msdn.microsoft.com/en-us/library/office/gg575571.aspx
/// </summary>
[Test]
public void WriteOutExcelFile()
{
var fileName = "ExcelFiles\\File_With_Many_Tabs.xlsx";
var sheetName = "Submission Form"; // Existing tab name.
using (var document = SpreadsheetDocument.Open(fileName, isEditable: false))
{
var workbookPart = document.WorkbookPart;
var sheet = workbookPart.Workbook.Descendants<Sheet>().FirstOrDefault(s => s.Name == sheetName);
var worksheetPart = (WorksheetPart)(workbookPart.GetPartById(sheet.Id));
var sheetData = worksheetPart.Worksheet.Elements<SheetData>().First();
foreach (var row in sheetData.Elements<Row>())
{
foreach (var cell in row.Elements<Cell>())
{
Console.Write("|" + GetCellValue(cell, workbookPart));
}
Console.Write("\n");
}
}
}
/// <summary>
/// Got code from: https://msdn.microsoft.com/en-us/library/office/hh298534.aspx
/// </summary>
/// <param name="cell"></param>
/// <param name="workbookPart"></param>
/// <returns></returns>
private string GetCellValue(Cell cell, WorkbookPart workbookPart)
{
if (cell == null)
{
return null;
}
var value = cell.CellFormula != null
? cell.CellValue.InnerText
: cell.InnerText.Trim();
// If the cell represents an integer number, you are done.
// For dates, this code returns the serialized value that
// represents the date. The code handles strings and
// Booleans individually. For shared strings, the code
// looks up the corresponding value in the shared string
// table. For Booleans, the code converts the value into
// the words TRUE or FALSE.
if (cell.DataType == null)
{
return value;
}
switch (cell.DataType.Value)
{
case CellValues.SharedString:
// For shared strings, look up the value in the
// shared strings table.
var stringTable =
workbookPart.GetPartsOfType<SharedStringTablePart>()
.FirstOrDefault();
// If the shared string table is missing, something
// is wrong. Return the index that is in
// the cell. Otherwise, look up the correct text in
// the table.
if (stringTable != null)
{
value =
stringTable.SharedStringTable
.ElementAt(int.Parse(value)).InnerText;
}
break;
case CellValues.Boolean:
switch (value)
{
case "0":
value = "FALSE";
break;
default:
value = "TRUE";
break;
}
break;
}
return value;
}

Use OLEDB Connection to communicate with excel files. it gives better result
using System.Data.OleDb;
string physicalPath = "Your Excel file physical path";
OleDbCommand cmd = new OleDbCommand();
OleDbDataAdapter da = new OleDbDataAdapter();
DataSet ds = new DataSet();
String strNewPath = physicalPath;
String connString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + strNewPath + ";Extended Properties=\"Excel 12.0;HDR=Yes;IMEX=2\"";
String query = "SELECT * FROM [Sheet1$]"; // You can use any different queries to get the data from the excel sheet
OleDbConnection conn = new OleDbConnection(connString);
if (conn.State == ConnectionState.Closed) conn.Open();
try
{
cmd = new OleDbCommand(query, conn);
da = new OleDbDataAdapter(cmd);
da.Fill(ds);
}
catch
{
// Exception Msg
}
finally
{
da.Dispose();
conn.Close();
}
The Output data will be stored in dataset, using the dataset object you can easily access the datas.
Hope this may helpful

Using OlebDB, we can read excel file in C#, easily, here is the code while working with Web-Form, where FileUpload1 is file uploading tool
string path = Server.MapPath("~/Uploads/");
if (!Directory.Exists(path))
{
Directory.CreateDirectory(path);
}
//get file path
filePath = path + Path.GetFileName(FileUpload1.FileName);
//get file extenstion
string extension = Path.GetExtension(FileUpload1.FileName);
//save file on "Uploads" folder of project
FileUpload1.SaveAs(filePath);
string conString = string.Empty;
//check file extension
switch (extension)
{
case ".xls": //Excel 97-03.
conString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=Excel03ConString;Extended Properties='Excel 8.0;HDR=YES'";
break;
case ".xlsx": //Excel 07 and above.
conString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=Excel07ConString;Extended Properties='Excel 8.0;HDR=YES'";
break;
}
//create datatable object
DataTable dt = new DataTable();
conString = string.Format(conString, filePath);
//Use OldDb to read excel
using (OleDbConnection connExcel = new OleDbConnection(conString))
{
using (OleDbCommand cmdExcel = new OleDbCommand())
{
using (OleDbDataAdapter odaExcel = new OleDbDataAdapter())
{
cmdExcel.Connection = connExcel;
//Get the name of First Sheet.
connExcel.Open();
DataTable dtExcelSchema;
dtExcelSchema = connExcel.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);
string sheetName = dtExcelSchema.Rows[0]["TABLE_NAME"].ToString();
connExcel.Close();
//Read Data from First Sheet.
connExcel.Open();
cmdExcel.CommandText = "SELECT * From [" + sheetName + "]";
odaExcel.SelectCommand = cmdExcel;
odaExcel.Fill(dt);
connExcel.Close();
}
}
}
//bind datatable with GridView
GridView1.DataSource = dt;
GridView1.DataBind();
Source : https://qawithexperts.com/article/asp-net/read-excel-file-and-import-data-into-gridview-using-datatabl/209
Console application similar code example
https://qawithexperts.com/article/c-sharp/read-excel-file-in-c-console-application-example-using-oledb/168
If you need don't want to use OleDB, you can try https://github.com/ExcelDataReader/ExcelDataReader
which seems to have the ability to handle both formats (.xls and .xslx)

Excel File Reader & Writer Without Excel On u'r System
Download and add the dll for
NPOI u'r project.
Using this code to read a excel file.
using (FileStream file = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
{
XSSFWorkbook XSSFWorkbook = new XSSFWorkbook(file);
}
ISheet objxlWorkSheet = XSSFWorkbook.GetSheetAt(0);
int intRowCount = 1;
int intColumnCount = 0;
for (; ; )
{
IRow Row = objxlWorkSheet.GetRow(intRowCount);
if (Row != null)
{
ICell Cell = Row.GetCell(0);
ICell objCell = objxlWorkSheet.GetRow(intRowCount).GetCell(intColumnCount); }}

You can use ExcelDataReader see GitHub
You need to install nugets :
-ExcelDataReader
-ExcelDataReader.DataSet
using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.IO;
using ExcelDataReader;
using System.Text;
/// <summary>
/// Excel parsing in this class is performed by using a common shareware Lib found on:
/// https://github.com/ExcelDataReader/ExcelDataReader
/// </summary>
public static class ExcelParser
{
/// <summary>
/// Load, read and get values from Excel sheet
/// </summary>
public static List<FileRow> GetExcelRows(string path, string sheetName, bool skipFirstLine)
{
if (File.Exists(path))
{
return GetValues(path, sheetName, skipFirstLine);
}
else
throw new Exception("The process cannot access the file");
}
/// <summary>
/// Parse sheet names from given Excel file.
/// </summary>
public static List<string> GetSheetNames(string path)
{
using (var stream = new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.Read))
{
Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);
using (var excelReader = GetExcelDataReader(path, stream))
{
var dataset = excelReader.AsDataSet(new ExcelDataSetConfiguration()
{
ConfigureDataTable = (_) => new ExcelDataTableConfiguration()
{
UseHeaderRow = true
}
});
var names = from DataTable table in dataset.Tables
select table.TableName;
return names.ToList();
}
}
}
/// <summary>
/// Parse values from Excel sheet and add to Rows collection.
/// </summary>
public static List<FileRow> GetValues(string path, string sheetName, bool skipFirstLine)
{
var rowItems = new List<FileRow>();
using (var stream = new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.Read))
{
using (var excelReader = GetExcelDataReader(path, stream))
{
var dataset = excelReader.AsDataSet(new ExcelDataSetConfiguration()
{
ConfigureDataTable = (_) => new ExcelDataTableConfiguration()
{
UseHeaderRow = skipFirstLine
}
});
foreach (DataRow row in dataset.Tables[sheetName].Rows)
{
var rowItem = new FileRow();
foreach (var value in row.ItemArray)
rowItem.Values.Add(value);
rowItems.Add(rowItem);
}
}
}
return rowItems;
}
private static IExcelDataReader GetExcelDataReader(string path, Stream stream)
{
var extension = GetExtension(path);
switch (extension)
{
case "xls":
return ExcelReaderFactory.CreateBinaryReader(stream);
case "xlsx":
return ExcelReaderFactory.CreateOpenXmlReader(stream);
default:
throw new Exception(string.Format("'{0}' is not a valid Excel extension", extension));
}
}
private static string GetExtension(string path)
{
var extension = Path.GetExtension(path);
return extension == null ? null : extension.ToLower().Substring(1);
}
}
With this entity :
public class FileRow
{
public List<object> Values { get; set; }
public FileRow()
{
Values = new List<object>();
}
}
Use like that :
var txtPath = #"D:\Path\excelfile.xlsx";
var sheetNames = ExcelParser.GetSheetNames(txtPath);
var datas = ExcelParser.GetExcelRows(txtPath, sheetNames[0], true);

The recommended way to read Excel files on server side app is Open XML.
Sharing few links -
https://msdn.microsoft.com/en-us/library/office/hh298534.aspx
https://msdn.microsoft.com/en-us/library/office/ff478410.aspx
https://msdn.microsoft.com/en-us/library/office/cc823095.aspx

public void excelRead(string sheetName)
{
Excel.Application appExl = new Excel.Application();
Excel.Workbook workbook = null;
try
{
string methodName = "";
Excel.Worksheet NwSheet;
Excel.Range ShtRange;
//Opening Excel file(myData.xlsx)
appExl = new Excel.Application();
workbook = appExl.Workbooks.Open(sheetName, Missing.Value, ReadOnly: false);
NwSheet = (Excel.Worksheet)workbook.Sheets.get_Item(1);
ShtRange = NwSheet.UsedRange; //gives the used cells in sheet
int rCnt1 = 0;
int cCnt1 = 0;
for (rCnt1 = 1; rCnt1 <= ShtRange.Rows.Count; rCnt1++)
{
for (cCnt1 = 1; cCnt1 <= ShtRange.Columns.Count; cCnt1++)
{
if (Convert.ToString(NwSheet.Cells[rCnt1, cCnt1].Value2) == "Y")
{
methodName = NwSheet.Cells[rCnt1, cCnt1 - 2].Value2;
Type metdType = this.GetType();
MethodInfo mthInfo = metdType.GetMethod(methodName);
if (Convert.ToString(NwSheet.Cells[rCnt1, cCnt1 - 2].Value2) == "fn_AddNum" || Convert.ToString(NwSheet.Cells[rCnt1, cCnt1 - 2].Value2) == "fn_SubNum")
{
StaticVariable.intParam1 = Convert.ToInt32(NwSheet.Cells[rCnt1, cCnt1 + 3].Value2);
StaticVariable.intParam2 = Convert.ToInt32(NwSheet.Cells[rCnt1, cCnt1 + 4].Value2);
object[] mParam1 = new object[] { StaticVariable.intParam1, StaticVariable.intParam2 };
object result = mthInfo.Invoke(this, mParam1);
StaticVariable.intOutParam1 = Convert.ToInt32(result);
NwSheet.Cells[rCnt1, cCnt1 + 5].Value2 = Convert.ToString(StaticVariable.intOutParam1) != "" ? Convert.ToString(StaticVariable.intOutParam1) : String.Empty;
}
else
{
object[] mParam = new object[] { };
mthInfo.Invoke(this, mParam);
NwSheet.Cells[rCnt1, cCnt1 + 5].Value2 = StaticVariable.outParam1 != "" ? StaticVariable.outParam1 : String.Empty;
NwSheet.Cells[rCnt1, cCnt1 + 6].Value2 = StaticVariable.outParam2 != "" ? StaticVariable.outParam2 : String.Empty;
}
NwSheet.Cells[rCnt1, cCnt1 + 1].Value2 = StaticVariable.resultOut;
NwSheet.Cells[rCnt1, cCnt1 + 2].Value2 = StaticVariable.resultDescription;
}
else if (Convert.ToString(NwSheet.Cells[rCnt1, cCnt1].Value2) == "N")
{
MessageBox.Show("Result is No");
}
else if (Convert.ToString(NwSheet.Cells[rCnt1, cCnt1].Value2) == "EOF")
{
MessageBox.Show("End of File");
}
}
}
workbook.Save();
workbook.Close(true, Missing.Value, Missing.Value);
appExl.Quit();
System.Runtime.InteropServices.Marshal.FinalReleaseComObject(ShtRange);
System.Runtime.InteropServices.Marshal.FinalReleaseComObject(NwSheet);
System.Runtime.InteropServices.Marshal.FinalReleaseComObject(workbook);
System.Runtime.InteropServices.Marshal.FinalReleaseComObject(appExl);
}
catch (Exception)
{
workbook.Close(true, Missing.Value, Missing.Value);
}
finally
{
GC.Collect();
GC.WaitForPendingFinalizers();
System.Runtime.InteropServices.Marshal.CleanupUnusedObjectsInCurrentContext();
}
}
//code for reading excel data in datatable
public void testExcel(string sheetName)
{
try
{
MessageBox.Show(sheetName);
foreach(Process p in Process.GetProcessesByName("EXCEL"))
{
p.Kill();
}
//string fileName = "E:\\inputSheet";
Excel.Application oXL;
Workbook oWB;
Worksheet oSheet;
Range oRng;
// creat a Application object
oXL = new Excel.Application();
// get WorkBook object
oWB = oXL.Workbooks.Open(sheetName);
// get WorkSheet object
oSheet = (Microsoft.Office.Interop.Excel.Worksheet)oWB.Sheets[1];
System.Data.DataTable dt = new System.Data.DataTable();
//DataSet ds = new DataSet();
//ds.Tables.Add(dt);
DataRow dr;
StringBuilder sb = new StringBuilder();
int jValue = oSheet.UsedRange.Cells.Columns.Count;
int iValue = oSheet.UsedRange.Cells.Rows.Count;
// get data columns
for (int j = 1; j <= jValue; j++)
{
oRng = (Microsoft.Office.Interop.Excel.Range)oSheet.Cells[1, j];
string strValue = oRng.Text.ToString();
dt.Columns.Add(strValue, System.Type.GetType("System.String"));
}
//string colString = sb.ToString().Trim();
//string[] colArray = colString.Split(':');
// get data in cell
for (int i = 2; i <= iValue; i++)
{
dr = dt.NewRow();
for (int j = 1; j <= jValue; j++)
{
oRng = (Microsoft.Office.Interop.Excel.Range)oSheet.Cells[i, j];
string strValue = oRng.Text.ToString();
dr[j - 1] = strValue;
}
dt.Rows.Add(dr);
}
if(StaticVariable.dtExcel != null)
{
StaticVariable.dtExcel.Clear();
StaticVariable.dtExcel = dt.Copy();
}
else
StaticVariable.dtExcel = dt.Copy();
oWB.Close(true, Missing.Value, Missing.Value);
oXL.Quit();
MessageBox.Show(sheetName);
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
finally
{
}
}
//code for class initialize
public static void startTesting(TestContext context)
{
Playback.Initialize();
ReadExcel myClassObj = new ReadExcel();
string sheetName="";
StreamReader sr = new StreamReader(#"E:\SaveSheetName.txt");
sheetName = sr.ReadLine();
sr.Close();
myClassObj.excelRead(sheetName);
myClassObj.testExcel(sheetName);
}
//code for test initalize
public void runValidatonTest()
{
DataTable dtFinal = StaticVariable.dtExcel.Copy();
for (int i = 0; i < dtFinal.Rows.Count; i++)
{
if (TestContext.TestName == dtFinal.Rows[i][2].ToString() && dtFinal.Rows[i][3].ToString() == "Y" && dtFinal.Rows[i][4].ToString() == "TRUE")
{
MessageBox.Show(TestContext.TestName);
MessageBox.Show(dtFinal.Rows[i][2].ToString());
StaticVariable.runValidateResult = "true";
break;
}
}
//StaticVariable.dtExcel = dtFinal.Copy();
}

I'd recommend you to use Bytescout Spreadsheet.
https://bytescout.com/products/developer/spreadsheetsdk/bytescoutspreadsheetsdk.html
I tried it with Monodevelop in Unity3D and it is pretty straight forward. Check this sample code to see how the library works:
https://bytescout.com/products/developer/spreadsheetsdk/read-write-excel.html

How to read all the rows of the excel sheet and run in Selenium test script using C#?

I need help reading all the rows from excel sheet as a test data in my selenium test case.
I can read only one row of an excel sheet with the following code.
//set up test for selenium
public void SetupTest()
{
selenium = new DefaultSelenium("localhost", 4444, "*googlechrome", "http://www.google.com/");
selenium.Start();
verificationErrors = new StringBuilder();
}
//Connects me to my excel sheet which is SampleTestData.xls
public void ConnectExcel()
{
excel.Application excelApp = new excel.Application();
excelApp.Visible = true;
string ExcelDataPath = #"C:\SampleTestData.xls";
excel.Workbook excelWorkBook = excelApp.Workbooks.Open(ExcelDataPath, 0, false, 5, "", "", false, excel.XlPlatform.xlWindows, "", true, false, 0, true, false, false);
excel.Sheets excelSheets = excelWorkBook.Worksheets;
excel.Worksheet DataworkSheet = (excel.Worksheet)excelSheets.get_Item("Sheet1");
System.String Search1 = ((excel.Range)DataworkSheet.get_Range("A1", Type.Missing)).Value2 as string;
}
//selenium code to run the test
public void StartTest()
{
selenium.open("");
selenium.WaitForPageToLoad("100000");
selenium.Type("gbqfif", search1);
selenium.Click("btnG");
selenium.WaitForPageToLoad("100000");
}
This code lets me select only one row that contains value of search1. However, I need to iterate it such a way that it will keep running StartTest() method until all the rows(50) in the excel sheet are entered.
Any help would be appreciated.

This answer may or may not help you but I am going to take a chance and post 2 samples of code that you can use..
Example #1
using System;
using System.Windows.Forms;
using Excel = Microsoft.Office.Interop.Excel;
namespace WindowsApplication1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
Excel.Application xlApp ;
Excel.Workbook xlWorkBook ;
Excel.Worksheet xlWorkSheet ;
Excel.Range range ;
string str;
int rCnt = 0;
int cCnt = 0;
xlApp = new Excel.ApplicationClass();
xlWorkBook = xlApp.Workbooks.Open("csharp.net-informations.xls", 0, true, 5, "", "", true, Microsoft.Office.Interop.Excel.XlPlatform.xlWindows, "\t", false, false, 0, true, 1, 0);
xlWorkSheet = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(1);
range = xlWorkSheet.UsedRange;
for (rCnt = 1; rCnt <= range.Rows.Count; rCnt++)
{
for (cCnt = 1; cCnt <= range.Columns.Count; cCnt++)
{
str = (string)(range.Cells[rCnt, cCnt] as Excel.Range).Value2 ;
MessageBox.Show(str);
}
}
xlWorkBook.Close(true, null, null);
xlApp.Quit();
releaseObject(xlWorkSheet);
releaseObject(xlWorkBook);
releaseObject(xlApp);
}
private void releaseObject(object obj)
{
try
{
System.Runtime.InteropServices.Marshal.ReleaseComObject(obj);
obj = null;
}
catch (Exception ex)
{
obj = null;
MessageBox.Show("Unable to release the Object " + ex.ToString());
}
finally
{
GC.Collect();
}
}
}
}
Example #2
FileStream stream = File.Open(filePath, FileMode.Open, FileAccess.Read);
//1. Reading from a binary Excel file ('97-2003 format; *.xls)
IExcelDataReader excelReader = ExcelReaderFactory.CreateBinaryReader(stream);
//...
//2. Reading from a OpenXml Excel file (2007 format; *.xlsx)
IExcelDataReader excelReader = ExcelReaderFactory.CreateOpenXmlReader(stream);
//...
//3. DataSet - The result of each spreadsheet will be created in the result.Tables
DataSet result = excelReader.AsDataSet();
//...
//4. DataSet - Create column names from first row
excelReader.IsFirstRowAsColumnNames = true;
DataSet result = excelReader.AsDataSet();
//5. Data Reader methods
while (excelReader.Read())
{
//excelReader.GetInt32(0);
}
//6. Free resources (IExcelDataReader is IDisposable)
excelReader.Close();
Example #3
using (FileStream fileStream = File.Open(inputFilenames[0], FileMode.Open, FileAccess.Read))
{
IExcelDataReader excelReader;
if (Path.GetExtension(inputFilenames[0]) == ".xls")
excelReader = Factory.CreateReader(fileStream, ExcelFileType.Binary);
else
excelReader = Factory.CreateReader(fileStream, ExcelFileType.OpenXml);
excelReader.NextResult();
while (excelReader.Name != this.Worksheet)
excelReader.NextResult();
while (excelReader.Read())
{
if (FirstRowHasColumnNames)
{
FirstRowHasColumnNames = false;
}
else
{
//do stuff
var test = GetColumnData(excelReader, 1);
}
}
this.Save(outputFilename);
}
you can look at this link as well
Reading from Excel File

Try this:-
//Reading from a OpenXml Excel file (2007 format; *.xlsx)
IExcelDataReader excelReader = ExcelReaderFactory.CreateOpenXmlReader(stream);
// DataSet - Create column names from first row
excelReader.IsFirstRowAsColumnNames = true;
DataSet result = excelReader.AsDataSet();
while (excelReader.Read())
{ // Reading from row and get columns by index
var test = excelReader.GetString(1);
}

How to read data of an Excel file using C#?

How to read an Excel file using C#? I open an Excel file for reading and copy it to clipboard to search email format, but I don't know how to do it.
FileInfo finfo;
Excel.ApplicationClass ExcelObj = new Excel.ApplicationClass();
ExcelObj.Visible = false;
Excel.Workbook theWorkbook;
Excel.Worksheet worksheet;
if (listView1.Items.Count > 0)
{
foreach (ListViewItem s in listView1.Items)
{
finfo = new FileInfo(s.Text);
if (finfo.Extension == ".xls" || finfo.Extension == ".xlsx" || finfo.Extension == ".xlt" || finfo.Extension == ".xlsm" || finfo.Extension == ".csv")
{
theWorkbook = ExcelObj.Workbooks.Open(s.Text, 0, true, 5, "", "", true, Excel.XlPlatform.xlWindows, "\t", false, false, 0, true, false, false);
for (int count = 1; count <= theWorkbook.Sheets.Count; count++)
{
worksheet = (Excel.Worksheet)theWorkbook.Worksheets.get_Item(count);
worksheet.Activate();
worksheet.Visible = false;
worksheet.UsedRange.Cells.Select();
}
}
}
}

OK,
One of the more difficult concepts to grasp about Excel VSTO programming is that you don't refer to cells like an array, Worksheet[0][0] won't give you cell A1, it will error out on you. Even when you type into A1 when Excel is open, you are actually entering data into Range A1. Therefore you refer to cells as Named Ranges. Here's an example:
Excel.Worksheet sheet = workbook.Sheets["Sheet1"] as Excel.Worksheet;
Excel.Range range = sheet.get_Range("A1", Missing.Value)
You can now literally type:
range.Text // this will give you the text the user sees
range.Value2 // this will give you the actual value stored by Excel (without rounding)
If you want to do something like this:
Excel.Range range = sheet.get_Range("A1:A5", Missing.Value)
if (range1 != null)
foreach (Excel.Range r in range1)
{
string user = r.Text
string value = r.Value2
}
There might be a better way, but this has worked for me.
The reason you need to use Value2 and not Value is because the Value property is a parametrized and C# doesn't support them yet.
As for the cleanup code, i will post that when i get to work tomorrow, i don't have the code with me, but it's very boilerplate. You just close and release the objects in the reverse order you created them. You can't use a Using() block because the Excel.Application or Excel.Workbook doesn't implement IDisposable, and if you don't clean-up, you will be left with a hanging Excel objects in memory.
Note:
If you don't set the Visibility property Excel doesn't display, which can be disconcerting to your users, but if you want to just rip the data out, that is probably good enough
You could OleDb, that will work too.
I hope that gets you started, let me know if you need further clarification. I'll post a complete
here is a complete sample:
using System;
using System.IO;
using System.Reflection;
using NUnit.Framework;
using ExcelTools = Ms.Office;
using Excel = Microsoft.Office.Interop.Excel;
namespace Tests
{
[TestFixture]
public class ExcelSingle
{
[Test]
public void ProcessWorkbook()
{
string file = #"C:\Users\Chris\Desktop\TestSheet.xls";
Console.WriteLine(file);
Excel.Application excel = null;
Excel.Workbook wkb = null;
try
{
excel = new Excel.Application();
wkb = ExcelTools.OfficeUtil.OpenBook(excel, file);
Excel.Worksheet sheet = wkb.Sheets["Data"] as Excel.Worksheet;
Excel.Range range = null;
if (sheet != null)
range = sheet.get_Range("A1", Missing.Value);
string A1 = String.Empty;
if( range != null )
A1 = range.Text.ToString();
Console.WriteLine("A1 value: {0}", A1);
}
catch(Exception ex)
{
//if you need to handle stuff
Console.WriteLine(ex.Message);
}
finally
{
if (wkb != null)
ExcelTools.OfficeUtil.ReleaseRCM(wkb);
if (excel != null)
ExcelTools.OfficeUtil.ReleaseRCM(excel);
}
}
}
}
I'll post the functions from ExcelTools tomorrow, I don't have that code with me either.
Edit:
As promised, here are the Functions from ExcelTools you might need.
public static Excel.Workbook OpenBook(Excel.Application excelInstance, string fileName, bool readOnly, bool editable,
bool updateLinks) {
Excel.Workbook book = excelInstance.Workbooks.Open(
fileName, updateLinks, readOnly,
Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing,
Type.Missing, editable, Type.Missing, Type.Missing, Type.Missing,
Type.Missing, Type.Missing);
return book;
}
public static void ReleaseRCM(object o) {
try {
System.Runtime.InteropServices.Marshal.ReleaseComObject(o);
} catch {
} finally {
o = null;
}
}
To be frank, this stuff is much easier if you use VB.NET. It's in C# because I didn't write it. VB.NET does option parameters well, C# does not, hence the Type.Missing. Once you typed Type.Missing twice in a row, you run screaming from the room!
As for you question, you can try to following:
http://msdn.microsoft.com/en-us/library/microsoft.office.interop.excel.range.find(VS.80).aspx
I will post an example when I get back from my meeting... cheers
Edit: Here is an example
range = sheet.Cells.Find("Value to Find",
Type.Missing,
Type.Missing,
Type.Missing,
Type.Missing,
Excel.XlSearchDirection.xlNext,
Type.Missing,
Type.Missing, Type.Missing);
range.Text; //give you the value found
Here is another example inspired by this site:
range = sheet.Cells.Find("Value to find", Type.Missing, Type.Missing,Excel.XlLookAt.xlWhole,Excel.XlSearchOrder.xlByColumns,Excel.XlSearchDirection.xlNext,false, false, Type.Missing);
It helps to understand the parameters.
P.S. I'm one of those weird people who enjoys learning COM automation. All this code steamed from a tool I wrote for work which required me to process over 1000+ spreadsheets from the lab each Monday.

You can use Microsoft.Office.Interop.Excel assembly to process excel files.
Right click on your project and go to Add reference. Add the
Microsoft.Office.Interop.Excel assembly.
Include using
Microsoft.Office.Interop.Excel; to make use of assembly.
Here is the sample code:
using Microsoft.Office.Interop.Excel;
//create the Application object we can use in the member functions.
Microsoft.Office.Interop.Excel.Application _excelApp = new Microsoft.Office.Interop.Excel.Application();
_excelApp.Visible = true;
string fileName = "C:\\sampleExcelFile.xlsx";
//open the workbook
Workbook workbook = _excelApp.Workbooks.Open(fileName,
Type.Missing, Type.Missing, Type.Missing, Type.Missing,
Type.Missing, Type.Missing, Type.Missing, Type.Missing,
Type.Missing, Type.Missing, Type.Missing, Type.Missing,
Type.Missing, Type.Missing);
//select the first sheet
Worksheet worksheet = (Worksheet)workbook.Worksheets[1];
//find the used range in worksheet
Range excelRange = worksheet.UsedRange;
//get an object array of all of the cells in the worksheet (their values)
object[,] valueArray = (object[,])excelRange.get_Value(
XlRangeValueDataType.xlRangeValueDefault);
//access the cells
for (int row = 1; row <= worksheet.UsedRange.Rows.Count; ++row)
{
for (int col = 1; col <= worksheet.UsedRange.Columns.Count; ++col)
{
//access each cell
Debug.Print(valueArray[row, col].ToString());
}
}
//clean up stuffs
workbook.Close(false, Type.Missing, Type.Missing);
Marshal.ReleaseComObject(workbook);
_excelApp.Quit();
Marshal.FinalReleaseComObject(_excelApp);

Why don't you create OleDbConnection? There are a lot of available resources in the Internet. Here is an example
OleDbConnection con = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source="+filename+";Extended Properties=Excel 8.0");
con.Open();
try
{
//Create Dataset and fill with imformation from the Excel Spreadsheet for easier reference
DataSet myDataSet = new DataSet();
OleDbDataAdapter myCommand = new OleDbDataAdapter(" SELECT * FROM ["+listname+"$]" , con);
myCommand.Fill(myDataSet);
con.Close();
richTextBox1.AppendText("\nDataSet Filled");
//Travers through each row in the dataset
foreach (DataRow myDataRow in myDataSet.Tables[0].Rows)
{
//Stores info in Datarow into an array
Object[] cells = myDataRow.ItemArray;
//Traverse through each array and put into object cellContent as type Object
//Using Object as for some reason the Dataset reads some blank value which
//causes a hissy fit when trying to read. By using object I can convert to
//String at a later point.
foreach (object cellContent in cells)
{
//Convert object cellContect into String to read whilst replacing Line Breaks with a defined character
string cellText = cellContent.ToString();
cellText = cellText.Replace("\n", "|");
//Read the string and put into Array of characters chars
richTextBox1.AppendText("\n"+cellText);
}
}
//Thread.Sleep(15000);
}
catch (Exception ex)
{
MessageBox.Show(ex.ToString());
//Thread.Sleep(15000);
}
finally
{
con.Close();
}

try
{
DataTable sheet1 = new DataTable("Excel Sheet");
OleDbConnectionStringBuilder csbuilder = new OleDbConnectionStringBuilder();
csbuilder.Provider = "Microsoft.ACE.OLEDB.12.0";
csbuilder.DataSource = fileLocation;
csbuilder.Add("Extended Properties", "Excel 12.0 Xml;HDR=YES");
string selectSql = #"SELECT * FROM [Sheet1$]";
using (OleDbConnection connection = new OleDbConnection(csbuilder.ConnectionString))
using (OleDbDataAdapter adapter = new OleDbDataAdapter(selectSql, connection))
{
connection.Open();
adapter.Fill(sheet1);
}
}
catch (Exception e)
{
Console.WriteLine(e.Message);
}
This worked for me. Please try it and let me know for queries.

Here's a 2020 answer - if you don't need to support the older .xls format (so pre 2003) you could use either:
LightweightExcelReader to access specfic cells, or cursor through all the data in a spreadsheet.
or
ExcelToEnumerable if you want to map spreadsheet data to a list of objects.
Pros :
Performance - at the time of writing (the the fastest way to read an .xlsx file)[https://github.com/ChrisHodges/ExcelToEnumerable#performance].
Simplicity - less verbose than OLE DB or OpenXml
Cons:
Neither LightweightExcelReader nor ExcelToEnumerable support .xls files.
Disclaimer: I am the author of LightweightExcelReader and ExcelToEnumerable

Use Open XML.
Here is some code to process a spreadsheet with a specific tab or sheet name and dump it to something like CSV. (I chose a pipe instead of comma).
I wish it was easier to get the value from a cell, but I think this is what we are stuck with. You can see that I reference the MSDN documents where I got most of this code. That is what Microsoft recommends.
/// <summary>
/// Got code from: https://msdn.microsoft.com/en-us/library/office/gg575571.aspx
/// </summary>
[Test]
public void WriteOutExcelFile()
{
var fileName = "ExcelFiles\\File_With_Many_Tabs.xlsx";
var sheetName = "Submission Form"; // Existing tab name.
using (var document = SpreadsheetDocument.Open(fileName, isEditable: false))
{
var workbookPart = document.WorkbookPart;
var sheet = workbookPart.Workbook.Descendants<Sheet>().FirstOrDefault(s => s.Name == sheetName);
var worksheetPart = (WorksheetPart)(workbookPart.GetPartById(sheet.Id));
var sheetData = worksheetPart.Worksheet.Elements<SheetData>().First();
foreach (var row in sheetData.Elements<Row>())
{
foreach (var cell in row.Elements<Cell>())
{
Console.Write("|" + GetCellValue(cell, workbookPart));
}
Console.Write("\n");
}
}
}
/// <summary>
/// Got code from: https://msdn.microsoft.com/en-us/library/office/hh298534.aspx
/// </summary>
/// <param name="cell"></param>
/// <param name="workbookPart"></param>
/// <returns></returns>
private string GetCellValue(Cell cell, WorkbookPart workbookPart)
{
if (cell == null)
{
return null;
}
var value = cell.CellFormula != null
? cell.CellValue.InnerText
: cell.InnerText.Trim();
// If the cell represents an integer number, you are done.
// For dates, this code returns the serialized value that
// represents the date. The code handles strings and
// Booleans individually. For shared strings, the code
// looks up the corresponding value in the shared string
// table. For Booleans, the code converts the value into
// the words TRUE or FALSE.
if (cell.DataType == null)
{
return value;
}
switch (cell.DataType.Value)
{
case CellValues.SharedString:
// For shared strings, look up the value in the
// shared strings table.
var stringTable =
workbookPart.GetPartsOfType<SharedStringTablePart>()
.FirstOrDefault();
// If the shared string table is missing, something
// is wrong. Return the index that is in
// the cell. Otherwise, look up the correct text in
// the table.
if (stringTable != null)
{
value =
stringTable.SharedStringTable
.ElementAt(int.Parse(value)).InnerText;
}
break;
case CellValues.Boolean:
switch (value)
{
case "0":
value = "FALSE";
break;
default:
value = "TRUE";
break;
}
break;
}
return value;
}

Use OLEDB Connection to communicate with excel files. it gives better result
using System.Data.OleDb;
string physicalPath = "Your Excel file physical path";
OleDbCommand cmd = new OleDbCommand();
OleDbDataAdapter da = new OleDbDataAdapter();
DataSet ds = new DataSet();
String strNewPath = physicalPath;
String connString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + strNewPath + ";Extended Properties=\"Excel 12.0;HDR=Yes;IMEX=2\"";
String query = "SELECT * FROM [Sheet1$]"; // You can use any different queries to get the data from the excel sheet
OleDbConnection conn = new OleDbConnection(connString);
if (conn.State == ConnectionState.Closed) conn.Open();
try
{
cmd = new OleDbCommand(query, conn);
da = new OleDbDataAdapter(cmd);
da.Fill(ds);
}
catch
{
// Exception Msg
}
finally
{
da.Dispose();
conn.Close();
}
The Output data will be stored in dataset, using the dataset object you can easily access the datas.
Hope this may helpful

Using OlebDB, we can read excel file in C#, easily, here is the code while working with Web-Form, where FileUpload1 is file uploading tool
string path = Server.MapPath("~/Uploads/");
if (!Directory.Exists(path))
{
Directory.CreateDirectory(path);
}
//get file path
filePath = path + Path.GetFileName(FileUpload1.FileName);
//get file extenstion
string extension = Path.GetExtension(FileUpload1.FileName);
//save file on "Uploads" folder of project
FileUpload1.SaveAs(filePath);
string conString = string.Empty;
//check file extension
switch (extension)
{
case ".xls": //Excel 97-03.
conString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=Excel03ConString;Extended Properties='Excel 8.0;HDR=YES'";
break;
case ".xlsx": //Excel 07 and above.
conString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=Excel07ConString;Extended Properties='Excel 8.0;HDR=YES'";
break;
}
//create datatable object
DataTable dt = new DataTable();
conString = string.Format(conString, filePath);
//Use OldDb to read excel
using (OleDbConnection connExcel = new OleDbConnection(conString))
{
using (OleDbCommand cmdExcel = new OleDbCommand())
{
using (OleDbDataAdapter odaExcel = new OleDbDataAdapter())
{
cmdExcel.Connection = connExcel;
//Get the name of First Sheet.
connExcel.Open();
DataTable dtExcelSchema;
dtExcelSchema = connExcel.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);
string sheetName = dtExcelSchema.Rows[0]["TABLE_NAME"].ToString();
connExcel.Close();
//Read Data from First Sheet.
connExcel.Open();
cmdExcel.CommandText = "SELECT * From [" + sheetName + "]";
odaExcel.SelectCommand = cmdExcel;
odaExcel.Fill(dt);
connExcel.Close();
}
}
}
//bind datatable with GridView
GridView1.DataSource = dt;
GridView1.DataBind();
Source : https://qawithexperts.com/article/asp-net/read-excel-file-and-import-data-into-gridview-using-datatabl/209
Console application similar code example
https://qawithexperts.com/article/c-sharp/read-excel-file-in-c-console-application-example-using-oledb/168
If you need don't want to use OleDB, you can try https://github.com/ExcelDataReader/ExcelDataReader
which seems to have the ability to handle both formats (.xls and .xslx)

Excel File Reader & Writer Without Excel On u'r System
Download and add the dll for
NPOI u'r project.
Using this code to read a excel file.
using (FileStream file = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
{
XSSFWorkbook XSSFWorkbook = new XSSFWorkbook(file);
}
ISheet objxlWorkSheet = XSSFWorkbook.GetSheetAt(0);
int intRowCount = 1;
int intColumnCount = 0;
for (; ; )
{
IRow Row = objxlWorkSheet.GetRow(intRowCount);
if (Row != null)
{
ICell Cell = Row.GetCell(0);
ICell objCell = objxlWorkSheet.GetRow(intRowCount).GetCell(intColumnCount); }}

You can use ExcelDataReader see GitHub
You need to install nugets :
-ExcelDataReader
-ExcelDataReader.DataSet
using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.IO;
using ExcelDataReader;
using System.Text;
/// <summary>
/// Excel parsing in this class is performed by using a common shareware Lib found on:
/// https://github.com/ExcelDataReader/ExcelDataReader
/// </summary>
public static class ExcelParser
{
/// <summary>
/// Load, read and get values from Excel sheet
/// </summary>
public static List<FileRow> GetExcelRows(string path, string sheetName, bool skipFirstLine)
{
if (File.Exists(path))
{
return GetValues(path, sheetName, skipFirstLine);
}
else
throw new Exception("The process cannot access the file");
}
/// <summary>
/// Parse sheet names from given Excel file.
/// </summary>
public static List<string> GetSheetNames(string path)
{
using (var stream = new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.Read))
{
Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);
using (var excelReader = GetExcelDataReader(path, stream))
{
var dataset = excelReader.AsDataSet(new ExcelDataSetConfiguration()
{
ConfigureDataTable = (_) => new ExcelDataTableConfiguration()
{
UseHeaderRow = true
}
});
var names = from DataTable table in dataset.Tables
select table.TableName;
return names.ToList();
}
}
}
/// <summary>
/// Parse values from Excel sheet and add to Rows collection.
/// </summary>
public static List<FileRow> GetValues(string path, string sheetName, bool skipFirstLine)
{
var rowItems = new List<FileRow>();
using (var stream = new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.Read))
{
using (var excelReader = GetExcelDataReader(path, stream))
{
var dataset = excelReader.AsDataSet(new ExcelDataSetConfiguration()
{
ConfigureDataTable = (_) => new ExcelDataTableConfiguration()
{
UseHeaderRow = skipFirstLine
}
});
foreach (DataRow row in dataset.Tables[sheetName].Rows)
{
var rowItem = new FileRow();
foreach (var value in row.ItemArray)
rowItem.Values.Add(value);
rowItems.Add(rowItem);
}
}
}
return rowItems;
}
private static IExcelDataReader GetExcelDataReader(string path, Stream stream)
{
var extension = GetExtension(path);
switch (extension)
{
case "xls":
return ExcelReaderFactory.CreateBinaryReader(stream);
case "xlsx":
return ExcelReaderFactory.CreateOpenXmlReader(stream);
default:
throw new Exception(string.Format("'{0}' is not a valid Excel extension", extension));
}
}
private static string GetExtension(string path)
{
var extension = Path.GetExtension(path);
return extension == null ? null : extension.ToLower().Substring(1);
}
}
With this entity :
public class FileRow
{
public List<object> Values { get; set; }
public FileRow()
{
Values = new List<object>();
}
}
Use like that :
var txtPath = #"D:\Path\excelfile.xlsx";
var sheetNames = ExcelParser.GetSheetNames(txtPath);
var datas = ExcelParser.GetExcelRows(txtPath, sheetNames[0], true);

The recommended way to read Excel files on server side app is Open XML.
Sharing few links -
https://msdn.microsoft.com/en-us/library/office/hh298534.aspx
https://msdn.microsoft.com/en-us/library/office/ff478410.aspx
https://msdn.microsoft.com/en-us/library/office/cc823095.aspx

public void excelRead(string sheetName)
{
Excel.Application appExl = new Excel.Application();
Excel.Workbook workbook = null;
try
{
string methodName = "";
Excel.Worksheet NwSheet;
Excel.Range ShtRange;
//Opening Excel file(myData.xlsx)
appExl = new Excel.Application();
workbook = appExl.Workbooks.Open(sheetName, Missing.Value, ReadOnly: false);
NwSheet = (Excel.Worksheet)workbook.Sheets.get_Item(1);
ShtRange = NwSheet.UsedRange; //gives the used cells in sheet
int rCnt1 = 0;
int cCnt1 = 0;
for (rCnt1 = 1; rCnt1 <= ShtRange.Rows.Count; rCnt1++)
{
for (cCnt1 = 1; cCnt1 <= ShtRange.Columns.Count; cCnt1++)
{
if (Convert.ToString(NwSheet.Cells[rCnt1, cCnt1].Value2) == "Y")
{
methodName = NwSheet.Cells[rCnt1, cCnt1 - 2].Value2;
Type metdType = this.GetType();
MethodInfo mthInfo = metdType.GetMethod(methodName);
if (Convert.ToString(NwSheet.Cells[rCnt1, cCnt1 - 2].Value2) == "fn_AddNum" || Convert.ToString(NwSheet.Cells[rCnt1, cCnt1 - 2].Value2) == "fn_SubNum")
{
StaticVariable.intParam1 = Convert.ToInt32(NwSheet.Cells[rCnt1, cCnt1 + 3].Value2);
StaticVariable.intParam2 = Convert.ToInt32(NwSheet.Cells[rCnt1, cCnt1 + 4].Value2);
object[] mParam1 = new object[] { StaticVariable.intParam1, StaticVariable.intParam2 };
object result = mthInfo.Invoke(this, mParam1);
StaticVariable.intOutParam1 = Convert.ToInt32(result);
NwSheet.Cells[rCnt1, cCnt1 + 5].Value2 = Convert.ToString(StaticVariable.intOutParam1) != "" ? Convert.ToString(StaticVariable.intOutParam1) : String.Empty;
}
else
{
object[] mParam = new object[] { };
mthInfo.Invoke(this, mParam);
NwSheet.Cells[rCnt1, cCnt1 + 5].Value2 = StaticVariable.outParam1 != "" ? StaticVariable.outParam1 : String.Empty;
NwSheet.Cells[rCnt1, cCnt1 + 6].Value2 = StaticVariable.outParam2 != "" ? StaticVariable.outParam2 : String.Empty;
}
NwSheet.Cells[rCnt1, cCnt1 + 1].Value2 = StaticVariable.resultOut;
NwSheet.Cells[rCnt1, cCnt1 + 2].Value2 = StaticVariable.resultDescription;
}
else if (Convert.ToString(NwSheet.Cells[rCnt1, cCnt1].Value2) == "N")
{
MessageBox.Show("Result is No");
}
else if (Convert.ToString(NwSheet.Cells[rCnt1, cCnt1].Value2) == "EOF")
{
MessageBox.Show("End of File");
}
}
}
workbook.Save();
workbook.Close(true, Missing.Value, Missing.Value);
appExl.Quit();
System.Runtime.InteropServices.Marshal.FinalReleaseComObject(ShtRange);
System.Runtime.InteropServices.Marshal.FinalReleaseComObject(NwSheet);
System.Runtime.InteropServices.Marshal.FinalReleaseComObject(workbook);
System.Runtime.InteropServices.Marshal.FinalReleaseComObject(appExl);
}
catch (Exception)
{
workbook.Close(true, Missing.Value, Missing.Value);
}
finally
{
GC.Collect();
GC.WaitForPendingFinalizers();
System.Runtime.InteropServices.Marshal.CleanupUnusedObjectsInCurrentContext();
}
}
//code for reading excel data in datatable
public void testExcel(string sheetName)
{
try
{
MessageBox.Show(sheetName);
foreach(Process p in Process.GetProcessesByName("EXCEL"))
{
p.Kill();
}
//string fileName = "E:\\inputSheet";
Excel.Application oXL;
Workbook oWB;
Worksheet oSheet;
Range oRng;
// creat a Application object
oXL = new Excel.Application();
// get WorkBook object
oWB = oXL.Workbooks.Open(sheetName);
// get WorkSheet object
oSheet = (Microsoft.Office.Interop.Excel.Worksheet)oWB.Sheets[1];
System.Data.DataTable dt = new System.Data.DataTable();
//DataSet ds = new DataSet();
//ds.Tables.Add(dt);
DataRow dr;
StringBuilder sb = new StringBuilder();
int jValue = oSheet.UsedRange.Cells.Columns.Count;
int iValue = oSheet.UsedRange.Cells.Rows.Count;
// get data columns
for (int j = 1; j <= jValue; j++)
{
oRng = (Microsoft.Office.Interop.Excel.Range)oSheet.Cells[1, j];
string strValue = oRng.Text.ToString();
dt.Columns.Add(strValue, System.Type.GetType("System.String"));
}
//string colString = sb.ToString().Trim();
//string[] colArray = colString.Split(':');
// get data in cell
for (int i = 2; i <= iValue; i++)
{
dr = dt.NewRow();
for (int j = 1; j <= jValue; j++)
{
oRng = (Microsoft.Office.Interop.Excel.Range)oSheet.Cells[i, j];
string strValue = oRng.Text.ToString();
dr[j - 1] = strValue;
}
dt.Rows.Add(dr);
}
if(StaticVariable.dtExcel != null)
{
StaticVariable.dtExcel.Clear();
StaticVariable.dtExcel = dt.Copy();
}
else
StaticVariable.dtExcel = dt.Copy();
oWB.Close(true, Missing.Value, Missing.Value);
oXL.Quit();
MessageBox.Show(sheetName);
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
finally
{
}
}
//code for class initialize
public static void startTesting(TestContext context)
{
Playback.Initialize();
ReadExcel myClassObj = new ReadExcel();
string sheetName="";
StreamReader sr = new StreamReader(#"E:\SaveSheetName.txt");
sheetName = sr.ReadLine();
sr.Close();
myClassObj.excelRead(sheetName);
myClassObj.testExcel(sheetName);
}
//code for test initalize
public void runValidatonTest()
{
DataTable dtFinal = StaticVariable.dtExcel.Copy();
for (int i = 0; i < dtFinal.Rows.Count; i++)
{
if (TestContext.TestName == dtFinal.Rows[i][2].ToString() && dtFinal.Rows[i][3].ToString() == "Y" && dtFinal.Rows[i][4].ToString() == "TRUE")
{
MessageBox.Show(TestContext.TestName);
MessageBox.Show(dtFinal.Rows[i][2].ToString());
StaticVariable.runValidateResult = "true";
break;
}
}
//StaticVariable.dtExcel = dtFinal.Copy();
}

I'd recommend you to use Bytescout Spreadsheet.
https://bytescout.com/products/developer/spreadsheetsdk/bytescoutspreadsheetsdk.html
I tried it with Monodevelop in Unity3D and it is pretty straight forward. Check this sample code to see how the library works:
https://bytescout.com/products/developer/spreadsheetsdk/read-write-excel.html

c# (WinForms-App) export DataSet to Excel

I need a solution to export a dataset to an excel file without any asp code (HttpResonpsne...) but i did not find a good example to do this...
Best thanks in advance

I've created a class that exports a DataGridView or DataTable to an Excel file. You can probably change it a bit to make it use your DataSet instead (iterating through the DataTables in it). It also does some basic formatting which you could also extend.
To use it, simply call ExcelExport, and specify a filename and whether to open the file automatically or not after exporting. I also could have made them extension methods, but I didn't. Feel free to.
Note that Excel files can be saved as a glorified XML document and this makes use of that.
EDIT: This used to use a vanilla StreamWriter, but as pointed out, things would not be escaped correctly in many cases. Now it uses a XmlWriter, which will do the escaping for you.
The ExcelWriter class wraps an XmlWriter. I haven't bothered, but you might want to do a bit more error checking to make sure you can't write cell data before starting a row, and such. The code is below.
public class ExcelWriter : IDisposable
{
private XmlWriter _writer;
public enum CellStyle { General, Number, Currency, DateTime, ShortDate };
public void WriteStartDocument()
{
if (_writer == null) throw new InvalidOperationException("Cannot write after closing.");
_writer.WriteProcessingInstruction("mso-application", "progid=\"Excel.Sheet\"");
_writer.WriteStartElement("ss", "Workbook", "urn:schemas-microsoft-com:office:spreadsheet");
WriteExcelStyles();
}
public void WriteEndDocument()
{
if (_writer == null) throw new InvalidOperationException("Cannot write after closing.");
_writer.WriteEndElement();
}
private void WriteExcelStyleElement(CellStyle style)
{
_writer.WriteStartElement("Style", "urn:schemas-microsoft-com:office:spreadsheet");
_writer.WriteAttributeString("ID", "urn:schemas-microsoft-com:office:spreadsheet", style.ToString());
_writer.WriteEndElement();
}
private void WriteExcelStyleElement(CellStyle style, string NumberFormat)
{
_writer.WriteStartElement("Style", "urn:schemas-microsoft-com:office:spreadsheet");
_writer.WriteAttributeString("ID", "urn:schemas-microsoft-com:office:spreadsheet", style.ToString());
_writer.WriteStartElement("NumberFormat", "urn:schemas-microsoft-com:office:spreadsheet");
_writer.WriteAttributeString("Format", "urn:schemas-microsoft-com:office:spreadsheet", NumberFormat);
_writer.WriteEndElement();
_writer.WriteEndElement();
}
private void WriteExcelStyles()
{
_writer.WriteStartElement("Styles", "urn:schemas-microsoft-com:office:spreadsheet");
WriteExcelStyleElement(CellStyle.General);
WriteExcelStyleElement(CellStyle.Number, "General Number");
WriteExcelStyleElement(CellStyle.DateTime, "General Date");
WriteExcelStyleElement(CellStyle.Currency, "Currency");
WriteExcelStyleElement(CellStyle.ShortDate, "Short Date");
_writer.WriteEndElement();
}
public void WriteStartWorksheet(string name)
{
if (_writer == null) throw new InvalidOperationException("Cannot write after closing.");
_writer.WriteStartElement("Worksheet", "urn:schemas-microsoft-com:office:spreadsheet");
_writer.WriteAttributeString("Name", "urn:schemas-microsoft-com:office:spreadsheet", name);
_writer.WriteStartElement("Table", "urn:schemas-microsoft-com:office:spreadsheet");
}
public void WriteEndWorksheet()
{
if (_writer == null) throw new InvalidOperationException("Cannot write after closing.");
_writer.WriteEndElement();
_writer.WriteEndElement();
}
public ExcelWriter(string outputFileName)
{
XmlWriterSettings settings = new XmlWriterSettings();
settings.Indent = true;
_writer = XmlWriter.Create(outputFileName, settings);
}
public void Close()
{
if (_writer == null) throw new InvalidOperationException("Already closed.");
_writer.Close();
_writer = null;
}
public void WriteExcelColumnDefinition(int columnWidth)
{
if (_writer == null) throw new InvalidOperationException("Cannot write after closing.");
_writer.WriteStartElement("Column", "urn:schemas-microsoft-com:office:spreadsheet");
_writer.WriteStartAttribute("Width", "urn:schemas-microsoft-com:office:spreadsheet");
_writer.WriteValue(columnWidth);
_writer.WriteEndAttribute();
_writer.WriteEndElement();
}
public void WriteExcelUnstyledCell(string value)
{
if (_writer == null) throw new InvalidOperationException("Cannot write after closing.");
_writer.WriteStartElement("Cell", "urn:schemas-microsoft-com:office:spreadsheet");
_writer.WriteStartElement("Data", "urn:schemas-microsoft-com:office:spreadsheet");
_writer.WriteAttributeString("Type", "urn:schemas-microsoft-com:office:spreadsheet", "String");
_writer.WriteValue(value);
_writer.WriteEndElement();
_writer.WriteEndElement();
}
public void WriteStartRow()
{
if (_writer == null) throw new InvalidOperationException("Cannot write after closing.");
_writer.WriteStartElement("Row", "urn:schemas-microsoft-com:office:spreadsheet");
}
public void WriteEndRow()
{
if (_writer == null) throw new InvalidOperationException("Cannot write after closing.");
_writer.WriteEndElement();
}
public void WriteExcelStyledCell(object value, CellStyle style)
{
if (_writer == null) throw new InvalidOperationException("Cannot write after closing.");
_writer.WriteStartElement("Cell", "urn:schemas-microsoft-com:office:spreadsheet");
_writer.WriteAttributeString("StyleID", "urn:schemas-microsoft-com:office:spreadsheet", style.ToString());
_writer.WriteStartElement("Data", "urn:schemas-microsoft-com:office:spreadsheet");
switch (style)
{
case CellStyle.General:
_writer.WriteAttributeString("Type", "urn:schemas-microsoft-com:office:spreadsheet", "String");
break;
case CellStyle.Number:
case CellStyle.Currency:
_writer.WriteAttributeString("Type", "urn:schemas-microsoft-com:office:spreadsheet", "Number");
break;
case CellStyle.ShortDate:
case CellStyle.DateTime:
_writer.WriteAttributeString("Type", "urn:schemas-microsoft-com:office:spreadsheet", "DateTime");
break;
}
_writer.WriteValue(value);
// tag += String.Format("{1}\"><ss:Data ss:Type=\"DateTime\">{0:yyyy\\-MM\\-dd\\THH\\:mm\\:ss\\.fff}</ss:Data>", value,
_writer.WriteEndElement();
_writer.WriteEndElement();
}
public void WriteExcelAutoStyledCell(object value)
{
if (_writer == null) throw new InvalidOperationException("Cannot write after closing.");
//write the <ss:Cell> and <ss:Data> tags for something
if (value is Int16 || value is Int32 || value is Int64 || value is SByte ||
value is UInt16 || value is UInt32 || value is UInt64 || value is Byte)
{
WriteExcelStyledCell(value, CellStyle.Number);
}
else if (value is Single || value is Double || value is Decimal) //we'll assume it's a currency
{
WriteExcelStyledCell(value, CellStyle.Currency);
}
else if (value is DateTime)
{
//check if there's no time information and use the appropriate style
WriteExcelStyledCell(value, ((DateTime)value).TimeOfDay.CompareTo(new TimeSpan(0, 0, 0, 0, 0)) == 0 ? CellStyle.ShortDate : CellStyle.DateTime);
}
else
{
WriteExcelStyledCell(value, CellStyle.General);
}
}
#region IDisposable Members
public void Dispose()
{
if (_writer == null)
return;
_writer.Close();
_writer = null;
}
#endregion
}
Then you can export your DataTable using the following:
public static void ExcelExport(DataTable data, String fileName, bool openAfter)
{
//export a DataTable to Excel
DialogResult retry = DialogResult.Retry;
while (retry == DialogResult.Retry)
{
try
{
using (ExcelWriter writer = new ExcelWriter(fileName))
{
writer.WriteStartDocument();
// Write the worksheet contents
writer.WriteStartWorksheet("Sheet1");
//Write header row
writer.WriteStartRow();
foreach (DataColumn col in data.Columns)
writer.WriteExcelUnstyledCell(col.Caption);
writer.WriteEndRow();
//write data
foreach (DataRow row in data.Rows)
{
writer.WriteStartRow();
foreach (object o in row.ItemArray)
{
writer.WriteExcelAutoStyledCell(o);
}
writer.WriteEndRow();
}
// Close up the document
writer.WriteEndWorksheet();
writer.WriteEndDocument();
writer.Close();
if (openAfter)
OpenFile(fileName);
retry = DialogResult.Cancel;
}
}
catch (Exception myException)
{
retry = MessageBox.Show(myException.Message, "Excel Export", MessageBoxButtons.RetryCancel, MessageBoxIcon.Asterisk);
}
}
}

The following site demonstrates how to export a DataSet (or DataTable or List<>) into a "genuine" Excel 2007 .xlsx file.
It uses the OpenXML libraries, so you don't need to have Excel installed on your server.
C# ExportToExcel library
All of the source code is provided, free of charge, along with instructions using it with ASP.NET, ASP.NET Core 2+ or regular C#.
It's very easy to add to your own applications, you just need to call one function, passing in an Excel filename, and your data source:
DataSet ds = CreateSampleData();
string excelFilename = "C:\\Sample.xlsx";
CreateExcelFile.CreateExcelDocument(ds, excelFilename);
Hope this helps.

Creating excel files in .NET applications is quite common and similar questions have been asked several times before. For instance here and here. The last question asks about reading excel files, but most suggested solutions should work both ways.

This was a post with a really helpful top answer, but I found it was lacking because there was no simple way to import the XML file back into a datatable. I ended up having to write my own, and thought I would share it here in case anyone else was in the same boat (google was exceptionally unhelpful in that regard):
public static DataTable ImportExcelXML(string Filename)
{
//create a new dataset to load in the XML file
DataSet DS = new DataSet();
//Read the XML file into the dataset
DS.ReadXml(Filename);
//Create a new datatable to store the raw Data
DataTable Raw = new DataTable();
//assign the raw data from the file to the datatable
Raw = DS.Tables["Data"];
//count the number of columns in the XML file
int ColumnNumber = Raw.Columns.Count;
//create a datatable to store formatted Import Data
DataTable ImportData = new DataTable();
//create a string list to store the cell data of each row
List<string> RowData = new List<string>();
//loop through each row in the raw data table
for (int Counter = 0; Counter < Raw.Rows.Count; Counter++)
{
//if the data in the row is a colum header
if (Counter < ColumnNumber)
{
//add the column name to our formatted datatable
ImportData.Columns.Add(Raw.Rows[Counter].ItemArray.GetValue(1).ToString());
}
else
{
//if the row # (1 row = 1 cell from the excel file) from the raw datatable is divisable evenly by the number of columns in the formated import datatable AND this is not the 1st row of the raw table data after the headers
if ((Counter % ColumnNumber == 0) && (Counter != ColumnNumber))
{
//add the row we just built to the formatted import datatable
ImportData.Rows.Add(GenerateRow(ImportData, RowData));
//clear rowdata list in preperation for the next row
RowData.Clear();
}
//add the current cell data value from the raw datatable to the string list of cell values for the next row to be added to the formatted input datatable
RowData.Add(Raw.Rows[Counter].ItemArray.GetValue(1).ToString());
}
}
//add the final row
ImportData.Rows.Add(GenerateRow(ImportData, RowData));
return ImportData;
}
public static DataRow GenerateRow(DataTable ImportData, List<string> RowData)
{
//create a counter to keep track of the column position during row composition
int ColumnPosition = 0;
//make a new datarow based on the schema of the formated import datatable
DataRow NewRow = ImportData.NewRow();
//for each string cell value collected for the RowData list for this row
foreach (string CellData in RowData)
{
//add the cell value to the new datarow
NewRow[ImportData.Columns[ColumnPosition].ColumnName] = CellData;
//incriment column position in the new row
ColumnPosition++;
}
//return the generated row
return NewRow;
}

the code have problem with null values.
public void WriteExcelAutoStyledCell(object value)
{
//solve null values
if (value is DBNull) return;

I would have added this to the comments but I am new to stack so I am unable to comment. Using lc.'s solution I added another function that tests the strings characters for invalid XML characters. When I was exporting to excel on occasion there were characters that were found that were causing the export to fail.
You will need to modify one of the functions that is in lc's code.
public void WriteExcelAutoStyledCell(object value)
{
if (_writer == null) throw new InvalidOperationException("Cannot write after closing.");
string newValue = string.Empty;
try
{
//write the <ss:Cell> and <ss:Data> tags for something
if (value is Int16 || value is Int32 || value is Int64 || value is SByte ||
value is UInt16 || value is UInt32 || value is UInt64 || value is Byte)
{
WriteExcelStyledCell(value, CellStyle.Number);
}
else if (value is Single || value is Double || value is Decimal) //we'll assume it's a currency
{
WriteExcelStyledCell(value, CellStyle.Currency);
}
else if (value is DateTime)
{
//check if there's no time information and use the appropriate style
WriteExcelStyledCell(value, ((DateTime)value).TimeOfDay.CompareTo(new TimeSpan(0, 0, 0, 0, 0)) == 0 ? CellStyle.ShortDate : CellStyle.DateTime);
}
else
{
newValue = CheckXmlCompatibleValues(value.ToString()).ToString();
WriteExcelStyledCell(newValue, CellStyle.General);
}
}
catch (Exception thisException)
{
throw new InvalidOperationException(thisException.Message.ToString());
}
}
And add this function to 'ExcelWriter' class
public string CheckXmlCompatibleValues(string value)
{
string newValue = string.Empty;
bool found = false;
foreach (char c in value)
{
if (XmlConvert.IsXmlChar(c))
newValue += c.ToString();
else
found = true;
}
return newValue.ToString();
}
lc. Thanks for the code!

using XL = Microsoft.Office.Interop.Excel;
using System.Reflection;
public static void Datasource(DataTable dt)
{
XL.Application oXL;
XL._Workbook oWB;
XL._Worksheet oSheet;
XL.Range oRng;
try
{
oXL = new XL.Application();
Application.DoEvents();
oXL.Visible = false;
//Get a new workbook.
oWB = (XL._Workbook)(oXL.Workbooks.Add(Missing.Value));
oSheet = (XL._Worksheet)oWB.ActiveSheet;
//System.Data.DataTable dtGridData=ds.Tables[0];
int iRow = 2;
if (dt.Rows.Count > 0)
{
for (int j = 0; j < dt.Columns.Count; j++)
{
oSheet.Cells[1, j + 1] = dt.Columns[j].ColumnName;
}
// For each row, print the values of each column.
for (int rowNo = 0; rowNo < dt.Rows.Count; rowNo++)
{
for (int colNo = 0; colNo < dt.Columns.Count; colNo++)
{
oSheet.Cells[iRow, colNo + 1] = dt.Rows[rowNo][colNo].ToString();
}
iRow++;
}
iRow++;
}
oRng = oSheet.get_Range("A1", "IV1");
oRng.EntireColumn.AutoFit();
oXL.Visible = true;
}
catch (Exception theException)
{
throw theException;
}
finally
{
oXL = null;
oWB = null;
oSheet = null;
oRng = null;
}
}
Import from Excel to datatable:
DataTable dtTable = new DataTable();
DataColumn col = new DataColumn("Rfid");
dtTable.Columns.Add(col);
DataRow drRow;
Microsoft.Office.Interop.Excel.Application ExcelObj =
new Microsoft.Office.Interop.Excel.Application();
Microsoft.Office.Interop.Excel.Workbook theWorkbook =
ExcelObj.Workbooks.Open(txt_FilePath.Text, Type.Missing, Type.Missing, Type.Missing, Type.Missing,
Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing,
Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing);
Microsoft.Office.Interop.Excel.Sheets sheets = theWorkbook.Worksheets;
try
{
for (int sht = 1; sht <= sheets.Count; sht++)
{
Microsoft.Office.Interop.Excel.Worksheet worksheet =
(Microsoft.Office.Interop.Excel.Worksheet)sheets.get_Item(sht);
for (int i = 2; i <= worksheet.UsedRange.Rows.Count; i++)
{
Microsoft.Office.Interop.Excel.Range range = worksheet.get_Range("A" + i.ToString(), "B" + i.ToString());
System.Array myvalues = (System.Array)range.Cells.Value2;
String name = Convert.ToString(myvalues.GetValue(1, 1));
if (string.IsNullOrEmpty(name) == false)
{
drRow = dtTable.NewRow();
drRow["Rfid"] = name;
dtTable.Rows.Add(drRow);
}
}
Marshal.ReleaseComObject(worksheet);
worksheet = null;
}
return dtTable;
}
catch
{
throw;
}
finally
{
// Marshal.ReleaseComObject(worksheet);
Marshal.ReleaseComObject(sheets);
Marshal.ReleaseComObject(theWorkbook);
Marshal.ReleaseComObject(ExcelObj);
//worksheet = null;
sheets = null;
theWorkbook = null;
ExcelObj = null;
}

Microsoft has a built in solution for Importing/Exporting Excel files. It's not the most straightforward library but it generally works better than the others listed above.
The library required to do this is included in Office and can be found under the list of Framework assemblies at Microsoft.Office.Interop.Excel.
Here is some example code:
using Excel = Microsoft.Office.Interop.Excel;
Excel.Application app = new Excel.Application();
//Open existing workbook
//Excel.Workbook workbook = xlApp.Workbooks.Open(fileName);
//Create new workbook
Excel.Workbook workbook = app.Workbooks.Add();
Excel.Worksheet worksheet = workbook.ActiveSheet;
worksheet.Cells[1,1] = "Hello world!"; // Indexes start at 1, because Excel
workbook.SaveAs("C:\\MyWorkbook.xlsx");
workbook.Close();
app.Quit();

Develop Reference

C# (C-Sharp) is a programming language developed by Microsoft that runs on the .NET Framework.