Optimal way to Read an Excel file (.xls/.xlsx)

Optimal way to Read an Excel file (.xls/.xlsx) - c#

I know that there are different ways to read an Excel file:
Iterop
Oledb
Open Xml SDK
Compatibility is not a question because the program will be executed in a controlled environment.
My Requirement :
Read a file to a DataTable / CUstom Entities (I don't know how to make dynamic properties/fields to an object[column names will be variating in an Excel file])
Use DataTable/Custom Entities to perform some operations using its data.
Update DataTable with the results of the operations
Write it back to excel file.
Which would be simpler.
Also if possible advice me on custom Entities (adding properties/fields to an object dynamically)

Take a look at Linq-to-Excel. It's pretty neat.
var book = new LinqToExcel.ExcelQueryFactory(#"File.xlsx");
var query =
from row in book.Worksheet("Stock Entry")
let item = new
{
Code = row["Code"].Cast<string>(),
Supplier = row["Supplier"].Cast<string>(),
Ref = row["Ref"].Cast<string>(),
}
where item.Supplier == "Walmart"
select item;
It also allows for strongly-typed row access too.

I realize this question was asked nearly 7 years ago but it's still a top Google search result for certain keywords regarding importing excel data with C#, so I wanted to provide an alternative based on some recent tech developments.
Importing Excel data has become such a common task to my everyday duties, that I've streamlined the process and documented the method on my blog: best way to read excel file in c#.
I use NPOI because it can read/write Excel files without Microsoft Office installed and it doesn't use COM+ or any interops. That means it can work in the cloud!
But the real magic comes from pairing up with NPOI Mapper from Donny Tian because it allows me to map the Excel columns to properties in my C# classes without writing any code. It's beautiful.
Here is the basic idea:
I create a .net class that matches/maps the Excel columns I'm interested in:
class CustomExcelFormat
{
[Column("District")]
public int District { get; set; }
[Column("DM")]
public string FullName { get; set; }
[Column("Email Address")]
public string EmailAddress { get; set; }
[Column("Username")]
public string Username { get; set; }
public string FirstName
{
get
{
return Username.Split('.')[0];
}
}
public string LastName
{
get
{
return Username.Split('.')[1];
}
}
}
Notice, it allows me to map based on column name if I want to!
Then when I process the excel file all I need to do is something like this:
public void Execute(string localPath, int sheetIndex)
{
IWorkbook workbook;
using (FileStream file = new FileStream(localPath, FileMode.Open, FileAccess.Read))
{
workbook = WorkbookFactory.Create(file);
}
var importer = new Mapper(workbook);
var items = importer.Take<CustomExcelFormat>(sheetIndex);
foreach(var item in items)
{
var row = item.Value;
if (string.IsNullOrEmpty(row.EmailAddress))
continue;
UpdateUser(row);
}
DataContext.SaveChanges();
}
Now, admittedly, my code does not modify the Excel file itself. I am instead saving the data to a database using Entity Framework (that's why you see "UpdateUser" and "SaveChanges" in my example). But there is already a good discussion on SO about how to save/modify a file using NPOI.

Using OLE Query, it's quite simple (e.g. sheetName is Sheet1):
DataTable LoadWorksheetInDataTable(string fileName, string sheetName)
{
DataTable sheetData = new DataTable();
using (OleDbConnection conn = this.returnConnection(fileName))
{
conn.Open();
// retrieve the data using data adapter
OleDbDataAdapter sheetAdapter = new OleDbDataAdapter("select * from [" + sheetName + "$]", conn);
sheetAdapter.Fill(sheetData);
conn.Close();
}
return sheetData;
}
private OleDbConnection returnConnection(string fileName)
{
return new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + fileName + "; Jet OLEDB:Engine Type=5;Extended Properties=\"Excel 8.0;\"");
}
For newer Excel versions:
return new OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + fileName + ";Extended Properties=Excel 12.0;");
You can also use Excel Data Reader an open source project on CodePlex. Its works really well to export data from Excel sheets.
The sample code given on the link specified:
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();
Reference: How do I import from Excel to a DataSet using Microsoft.Office.Interop.Excel?

Try to use this free way to this, https://freenetexcel.codeplex.com
Workbook workbook = new Workbook();
workbook.LoadFromFile(#"..\..\parts.xls",ExcelVersion.Version97to2003);
//Initialize worksheet
Worksheet sheet = workbook.Worksheets[0];
DataTable dataTable = sheet.ExportDataTable();

If you can restrict it to just (Open Office XML format) *.xlsx files, then probably the most popular library would be EPPLus.
Bonus is, there are no other dependencies. Just install using nuget:
Install-Package EPPlus

Try to use Aspose.cells library (not free, but trial is enough to read), it is quite good
Install-package Aspose.cells
There is sample code:
using Aspose.Cells;
using System;
namespace ExcelReader
{
class Program
{
static void Main(string[] args)
{
// Replace path for your file
readXLS(#"C:\MyExcelFile.xls"); // or "*.xlsx"
Console.ReadKey();
}
public static void readXLS(string PathToMyExcel)
{
//Open your template file.
Workbook wb = new Workbook(PathToMyExcel);
//Get the first worksheet.
Worksheet worksheet = wb.Worksheets[0];
//Get cells
Cells cells = worksheet.Cells;
// Get row and column count
int rowCount = cells.MaxDataRow;
int columnCount = cells.MaxDataColumn;
// Current cell value
string strCell = "";
Console.WriteLine(String.Format("rowCount={0}, columnCount={1}", rowCount, columnCount));
for (int row = 0; row <= rowCount; row++) // Numeration starts from 0 to MaxDataRow
{
for (int column = 0; column <= columnCount; column++) // Numeration starts from 0 to MaxDataColumn
{
strCell = "";
strCell = Convert.ToString(cells[row, column].Value);
if (String.IsNullOrEmpty(strCell))
{
continue;
}
else
{
// Do your staff here
Console.WriteLine(strCell);
}
}
}
}
}
}

Read from excel, modify and write back
/// <summary>
/// /Reads an excel file and converts it into dataset with each sheet as each table of the dataset
/// </summary>
/// <param name="filename"></param>
/// <param name="headers">If set to true the first row will be considered as headers</param>
/// <returns></returns>
public DataSet Import(string filename, bool headers = true)
{
var _xl = new Excel.Application();
var wb = _xl.Workbooks.Open(filename);
var sheets = wb.Sheets;
DataSet dataSet = null;
if (sheets != null && sheets.Count != 0)
{
dataSet = new DataSet();
foreach (var item in sheets)
{
var sheet = (Excel.Worksheet)item;
DataTable dt = null;
if (sheet != null)
{
dt = new DataTable();
var ColumnCount = ((Excel.Range)sheet.UsedRange.Rows[1, Type.Missing]).Columns.Count;
var rowCount = ((Excel.Range)sheet.UsedRange.Columns[1, Type.Missing]).Rows.Count;
for (int j = 0; j < ColumnCount; j++)
{
var cell = (Excel.Range)sheet.Cells[1, j + 1];
var column = new DataColumn(headers ? cell.Value : string.Empty);
dt.Columns.Add(column);
}
for (int i = 0; i < rowCount; i++)
{
var r = dt.NewRow();
for (int j = 0; j < ColumnCount; j++)
{
var cell = (Excel.Range)sheet.Cells[i + 1 + (headers ? 1 : 0), j + 1];
r[j] = cell.Value;
}
dt.Rows.Add(r);
}
}
dataSet.Tables.Add(dt);
}
}
_xl.Quit();
return dataSet;
}
public string Export(DataTable dt, bool headers = false)
{
var wb = _xl.Workbooks.Add();
var sheet = (Excel.Worksheet)wb.ActiveSheet;
//process columns
for (int i = 0; i < dt.Columns.Count; i++)
{
var col = dt.Columns[i];
//added columns to the top of sheet
var currentCell = (Excel.Range)sheet.Cells[1, i + 1];
currentCell.Value = col.ToString();
currentCell.Font.Bold = true;
//process rows
for (int j = 0; j < dt.Rows.Count; j++)
{
var row = dt.Rows[j];
//added rows to sheet
var cell = (Excel.Range)sheet.Cells[j + 1 + 1, i + 1];
cell.Value = row[i];
}
currentCell.EntireColumn.AutoFit();
}
var fileName="{somepath/somefile.xlsx}";
wb.SaveCopyAs(fileName);
_xl.Quit();
return fileName;
}

I used Office's NuGet Package: DocumentFormat.OpenXml and pieced together the code from that component's doc site.
With the below helper code, was similar in complexity to my other CSV file format parsing in that project...
public static async Task ImportXLSX(Stream stream, string sheetName) {
{
// This was necessary for my Blazor project, which used a BrowserFileStream object
MemoryStream ms = new MemoryStream();
await stream.CopyToAsync(ms);
using (var document = SpreadsheetDocument.Open(ms, false))
{
// Retrieve a reference to the workbook part.
WorkbookPart wbPart = document.WorkbookPart;
// Find the sheet with the supplied name, and then use that
// Sheet object to retrieve a reference to the first worksheet.
Sheet theSheet = wbPart?.Workbook.Descendants<Sheet>().Where(s => s?.Name == sheetName).FirstOrDefault();
// Throw an exception if there is no sheet.
if (theSheet == null)
{
throw new ArgumentException("sheetName");
}
WorksheetPart wsPart = (WorksheetPart)(wbPart.GetPartById(theSheet.Id));
// For shared strings, look up the value in the
// shared strings table.
var stringTable =
wbPart.GetPartsOfType<SharedStringTablePart>()
.FirstOrDefault();
// I needed to grab 4 cells from each row
// Starting at row 11, until the cell in column A is blank
int row = 11;
while (true) {
var accountNameCell = GetCell(wsPart, "A" + row.ToString());
var accountName = GetValue(accountNameCell, stringTable);
if (string.IsNullOrEmpty(accountName)) {
break;
}
var investmentNameCell = GetCell(wsPart, "B" + row.ToString());
var investmentName = GetValue(investmentNameCell, stringTable);
var symbolCell = GetCell(wsPart, "D" + row.ToString());
var symbol = GetValue(symbolCell, stringTable);
var marketValue = GetCell(wsPart, "J" + row.ToString()).InnerText;
// DO STUFF with data
row++;
}
}
}
private static string? GetValue(Cell cell, SharedStringTablePart stringTable) {
try {
return stringTable.SharedStringTable.ElementAt(int.Parse(cell.InnerText)).InnerText;
} catch (Exception) {
return null;
}
}
private static Cell GetCell(WorksheetPart wsPart, string cellReference) {
return wsPart.Worksheet.Descendants<Cell>().Where(c => c.CellReference.Value == cellReference)?.FirstOrDefault();
}

Related

how to column names of excel sheet into list dynamically using asp.net [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 load on demand excel rows in a data table c#

I have a requirement where-in I have to fill dataTable from a sheet of Microsoft excel.
The sheet may have lots of data so the requirement is that when a foreach loop is iterated over the data table which is supposed to hold the data from Microsoft excel sheet should fill the table on demand.
Meaning if there are 1000000 records in the sheet the data table should fetch data in batches of 100 depending on the current position of the foreach current item in the loop.
Any pointer or suggestion will be appreciated.

I would suggest you to use OpenXML to parse and read your excel data from file.
This will also allow you to read out specific sections/regions from your workbook.
You will find more information and also an example at this link:
Microsoft Docs - Parse and read a large spreadsheet document (Open XML SDK)
This will be more efficiently and easier to develop than use the official microsoft office excel interop.

**I am not near a PC with Visual stuido, so this code is untested, and may have syntax errors until I can test it later.
It will still give you the main idea of what needs to be done.
private void ExcelDataPages(int firstRecord, int numberOfRecords)
{
Excel.Application dataApp = new Excel.Application();
Excel.Workbook dataWorkbook = new Excel.Workbook();
int x = 0;
dataWorkbook.DisplayAlerts = false;
dataWorkbook.Visible = false;
dataWorkbook.AutomationSecurity = Microsoft.Office.Core.MsoAutomationSecurity.msoAutomationSecurityLow;
dataWorkbook = dataApp.Open(#"C:\Test\YourWorkbook.xlsx");
try
{
Excel.Worksheet dataSheet = dataWorkbook.Sheet("Name of Sheet");
while (x < numberOfRecords)
{
Range currentRange = dataSheet.Rows[firstRecord + x]; //For all columns in row
foreach (Range r in currentRange.Cells) //currentRange represents all the columns in the row
{
// do what you need to with the Data here.
}
x++;
}
}
catch (Exception ex)
{
//Enter in Error handling
}
dataWorkbook.Close(false); //Depending on how quick you will access the next batch of data, you may not want to close the Workbook, reducing load time each time. This may also mean you need to move the open of the workbook to a higher level in your class, or if this is the main process of the app, make it static, stopping the garbage collector from destroying the connection.
dataApp.Quit();
}

Give the following a try--it uses NuGet package DocumentFormat.OpenXml The code is from Using OpenXmlReader. However, I modified it to add data to a DataTable. Since you're reading data from the same Excel file multiple times, it's faster to open the Excel file once using an instance of SpreadSheetDocument and dispose of it when finished. Since the instance of SpreedSheetDocument needs to be disposed of before your application exits, IDisposable is used.
Where it says "ToDo", you'll need to replace the code that creates the DataTable columns with your own code to create the correct columns for your project.
I tested the code below with an Excel file containing approximately 15,000 rows. When reading 100 rows at a time, the first read took approximately 500 ms - 800 ms, whereas subsequent reads took approximately 100 ms - 400 ms.
Create a class (name: HelperOpenXml)
HelperOpenXml.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using DocumentFormat.OpenXml;
using DocumentFormat.OpenXml.Packaging;
using DocumentFormat.OpenXml.Spreadsheet;
using System.Data;
using System.Diagnostics;
namespace ExcelReadSpecifiedRowsUsingOpenXml
{
public class HelperOpenXml : IDisposable
{
public string Filename { get; private set; } = string.Empty;
public int RowCount { get; private set; } = 0;
private SpreadsheetDocument spreadsheetDocument = null;
private DataTable dt = null;
public HelperOpenXml(string filename)
{
this.Filename = filename;
}
public void Dispose()
{
if (spreadsheetDocument != null)
{
try
{
spreadsheetDocument.Dispose();
dt.Clear();
}
catch(Exception ex)
{
throw ex;
}
}
}
public DataTable GetRowsSax(int startRow, int endRow, bool firstRowIsHeader = false)
{
int startIndex = startRow;
int endIndex = endRow;
if (firstRowIsHeader)
{
//if first row is header, increment by 1
startIndex = startRow + 1;
endIndex = endRow + 1;
}
if (spreadsheetDocument == null)
{
//create new instance
spreadsheetDocument = SpreadsheetDocument.Open(Filename, false);
//create new instance
dt = new DataTable();
//ToDo: replace 'dt.Columns.Add(...)' below with your code to create the DataTable columns
//add columns to DataTable
dt.Columns.Add("A");
dt.Columns.Add("B");
dt.Columns.Add("C");
dt.Columns.Add("D");
dt.Columns.Add("E");
dt.Columns.Add("F");
dt.Columns.Add("G");
dt.Columns.Add("H");
dt.Columns.Add("I");
dt.Columns.Add("J");
dt.Columns.Add("K");
}
else
{
//remove existing data from DataTable
dt.Rows.Clear();
}
WorkbookPart workbookPart = spreadsheetDocument.WorkbookPart;
int numWorkSheetParts = 0;
foreach (WorksheetPart worksheetPart in workbookPart.WorksheetParts)
{
using (OpenXmlReader reader = OpenXmlReader.Create(worksheetPart))
{
int rowIndex = 0;
//use the reader to read the XML
while (reader.Read())
{
if (reader.ElementType == typeof(Row))
{
reader.ReadFirstChild();
List<string> cValues = new List<string>();
int colIndex = 0;
do
{
//only get data from desired rows
if ((rowIndex > 0 && rowIndex >= startIndex && rowIndex <= endIndex) ||
(rowIndex == 0 && !firstRowIsHeader && rowIndex >= startIndex && rowIndex <= endIndex))
{
if (reader.ElementType == typeof(Cell))
{
Cell c = (Cell)reader.LoadCurrentElement();
string cellRef = c.CellReference; //ex: A1, B1, ..., A2, B2
string cellValue = string.Empty;
//string/text data is stored in SharedString
if (c.DataType != null && c.DataType == CellValues.SharedString)
{
SharedStringItem ssi = workbookPart.SharedStringTablePart.SharedStringTable.Elements<SharedStringItem>().ElementAt(int.Parse(c.CellValue.InnerText));
cellValue = ssi.Text.Text;
}
else
{
cellValue = c.CellValue.InnerText;
}
//Debug.WriteLine("{0}: {1} ", c.CellReference, cellValue);
//add value to List which is used to add a row to the DataTable
cValues.Add(cellValue);
}
}
colIndex += 1; //increment
} while (reader.ReadNextSibling());
if (cValues.Count > 0)
{
//if List contains data, use it to add row to DataTable
dt.Rows.Add(cValues.ToArray());
}
rowIndex += 1; //increment
if (rowIndex > endIndex)
{
break; //exit loop
}
}
}
}
numWorkSheetParts += 1; //increment
}
DisplayDataTableData(dt); //display data in DataTable
return dt;
}
private void DisplayDataTableData(DataTable dt)
{
foreach (DataColumn dc in dt.Columns)
{
Debug.WriteLine("colName: " + dc.ColumnName);
}
foreach (DataRow r in dt.Rows)
{
Debug.WriteLine(r[0].ToString() + " " + r[1].ToString());
}
}
}
}
Usage:
private string excelFilename = #"C:\Temp\Test.xlsx";
private HelperOpenXml helperOpenXml = null;
...
private void GetData(int startIndex, int endIndex, bool firstRowIsHeader)
{
helperOpenXml.GetRowsSax(startIndex, endIndex, firstRowIsHeader);
}
Note: Make sure to call Dispose() (ex: helperOpenXml.Dispose();) before your application exits.
Update:
OpenXML stores dates as the number of days since 01 Jan 1900. For dates prior to 01 Jan 1900, they are stored in SharedString. For more info see Reading a date from xlsx using open xml sdk
Here's a code snippet:
Cell c = (Cell)reader.LoadCurrentElement();
...
string cellValue = string.Empty
...
cellValue = c.CellValue.InnerText;
double dateCellValue = 0;
Double.TryParse(cellValue, out dateCellValue);
DateTime dt = DateTime.FromOADate(dateCellValue);
cellValue = dt.ToString("yyyy/MM/dd");

Another simple alternative is this: Take a look at the NUGET package ExcelDataReader, with additional information on
https://github.com/ExcelDataReader/ExcelDataReader
Usage example:
[Fact]
void Test_ExcelDataReader()
{
System.Text.Encoding.RegisterProvider(System.Text.CodePagesEncodingProvider.Instance);
var scriptPath = Path.GetDirectoryName(Util.CurrentQueryPath); // LinqPad script path
var filePath = $#"{scriptPath}\TestExcel.xlsx";
using (var stream = File.Open(filePath, FileMode.Open, FileAccess.Read))
{
// Auto-detect format, supports:
// - Binary Excel files (2.0-2003 format; *.xls)
// - OpenXml Excel files (2007 format; *.xlsx, *.xlsb)
using (var reader = ExcelDataReader.ExcelReaderFactory.CreateReader(stream))
{
var result = reader.AsDataSet();
// The result of each spreadsheet is in result.Tables
var t0 = result.Tables[0];
Assert.True(t0.Rows[0][0].Dump("R0C0").ToString()=="Hello", "Expected 'Hello'");
Assert.True(t0.Rows[0][1].Dump("R0C1").ToString()=="World!", "Expected 'World!'");
} // using
} // using
} // fact
Before you start reading, you need to set and encoding provider as follows:
System.Text.Encoding.RegisterProvider(
System.Text.CodePagesEncodingProvider.Instance);
The cells are addressed the following way:
var t0 = result.Tables[0]; // table 0 is the first worksheet
var cell = t0.Rows[0][0]; // on table t0, read cell row 0 column 0
And you can easily loop through the rows and columns in a for loop as follows:
for (int r = 0; r < t0.Rows.Count; r++)
{
var row = t0.Rows[r];
var columns = row.ItemArray;
for (int c = 0; c < columns.Length; c++)
{
var cell = columns[c];
cell.Dump();
}
}

I use this code with EPPlus DLL, Don't forget to add reference. But should check to match with your requirement.
public DataTable ReadExcelDatatable(bool hasHeader = true)
{
using (var pck = new OfficeOpenXml.ExcelPackage())
{
using (var stream = File.OpenRead(this._fullPath))
{
pck.Load(stream);
}
var ws = pck.Workbook.Worksheets.First();
DataTable tbl = new DataTable();
int i = 1;
foreach (var firstRowCell in ws.Cells[1, 1, 1, ws.Dimension.End.Column])
{
//table head
tbl.Columns.Add(hasHeader ? firstRowCell.Text : string.Format("Column {0}", firstRowCell.Start.Column));
tbl.Columns.Add(_tableHead[i]);
i++;
}
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;
}
}

I'm going to give you a different answer. If the performance is bad loading a million rows into a DataTable resort to using a Driver to load the data: How to open a huge excel file efficiently
DataSet excelDataSet = new DataSet();
string filePath = #"c:\temp\BigBook.xlsx";
// For .XLSXs we use =Microsoft.ACE.OLEDB.12.0;, for .XLS we'd use Microsoft.Jet.OLEDB.4.0; with "';Extended Properties=\"Excel 8.0;HDR=YES;\"";
string connectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source='" + filePath + "';Extended Properties=\"Excel 12.0;HDR=YES;\"";
using (OleDbConnection conn = new OleDbConnection(connectionString))
{
conn.Open();
OleDbDataAdapter objDA = new System.Data.OleDb.OleDbDataAdapter
("select * from [Sheet1$]", conn);
objDA.Fill(excelDataSet);
//dataGridView1.DataSource = excelDataSet.Tables[0];
}
Next filter the DataSet's DataTable using a DataView. Using a DataView's RowFilter property you can specify subsets of rows based on their column values.
DataView prodView = new DataView(excelDataSet.Tables[0],
"UnitsInStock <= ReorderLevel",
"SupplierID, ProductName",
DataViewRowState.CurrentRows);
Ref: https://www.c-sharpcorner.com/article/dataview-in-C-Sharp/
Or you could use the DataTables' DefaultView RowFilter directly:
excelDataSet.Tables[0].DefaultView.RowFilter = "Amount >= 5000 and Amount <= 5999 and Name = 'StackOverflow'";

Referencing an Excel file, workbook, worksheet in C#

All,
I have been struggling to simply reference an Excel file so that I can extract its data into a new worksheet automatically.
I know this means to create a new Excel file and its items:
Excel.Application oXL;
Excel._Workbook oWB;
Excel._Worksheet oSheet;
Excel.Range oRng;
//Start Excel and get Application object.
oXL = new Excel.Application();
oXL.Visible = true;
//Get a new workbook.
oWB = (Excel._Workbook)(oXL.Workbooks.Add(Missing.Value));
oSheet = (Excel._Worksheet)oWB.ActiveSheet;
But this is where I am lost...I want the user to select another Excel file through a file dialog and then I want to copy data from said file into the new workbook above.
Ex: New file, user selects "MyExcel.csv". How would I reference this so that I can, say, copy Column A into the new worksheet? Whatever works with C#.

Maybe this helps:
Make sure your manage your Nugets and add the reference "Microsoft.Office.Interop.Excel" --> (References (Right click) --> Manage Nuget Packages --> Browse --> "Microsoft.Office.Interop.Excel" --> Install)
Note: This is is a copy paste into the same worksheet. To copy the data into another worksheet from another file just pass the "worksheet" as parameter to the method and paste it there.
public class Excel1
{
private readonly string excelSufix = ".xlsx";
private readonly string excelFilePrefix = "..."; //Where you excel file is located
private string getFilePath(string fileName)
{
return excelFilePrefix + fileName + excelSufix; //returns the file path by the given file name
}
public void CopyPaste(string fileName, int worksheet, string toCopyRange, string whereInsertRange)
{
//Range should look like = "A:C" or "D:F"
var excelApp = new Microsoft.Office.Interop.Excel.Application();
excelApp.Visible = true;
var workBook = excelApp.Workbooks.Open(getFilePath(fileName));
var workSheet = (Microsoft.Office.Interop.Excel.Worksheet)workBook.Sheets[worksheet];
var toCopy = workSheet.Range[toCopyRange];
var whereInsert = workSheet.Range[whereInsertRange];
whereInsert.Insert(Microsoft.Office.Interop.Excel.XlInsertShiftDirection.xlShiftToRight, toCopy.Cut());
}
}
Edit: You could add a constructor to the class where you pass the file Path and some class variables which reference the file, the worksheet etc etc... In this case, you will have independent objects for each file

Based on your description, you want to copy one column from the csv file and paste in the new excel file.
First, I convert the csv file to datatable.
Second, I select the specific column and convert one column to datatable.
Third, I convert the datatable to the new excel file.
You can try the following code.
using System;
using System.Data;
using Excel = Microsoft.Office.Interop.Excel;
class Program
{
static void Main(string[] args)
{
string path = "D:\\t.csv";
DataTable table = ReadCsv(path);
table= new DataView(table).ToTable(false, "Tests");
ExportToExcel(table, "D:\\t.xlsx");
}
public static DataTable ReadCsv(string path)
{
Microsoft.Office.Interop.Excel.Application objXL = null;
Microsoft.Office.Interop.Excel.Workbook objWB = null;
objXL = new Microsoft.Office.Interop.Excel.Application();
objWB = objXL.Workbooks.Open(path);
Microsoft.Office.Interop.Excel.Worksheet objSHT = objWB.Worksheets[1];
int rows = objSHT.UsedRange.Rows.Count;
int cols = objSHT.UsedRange.Columns.Count;
DataTable dt = new DataTable();
int noofrow = 1;
for (int c = 1; c <= cols; c++)
{
string colname = objSHT.Cells[1, c].Text;
dt.Columns.Add(colname);
noofrow = 2;
}
for (int r = noofrow; r <= rows; r++)
{
DataRow dr = dt.NewRow();
for (int c = 1; c <= cols; c++)
{
dr[c - 1] = objSHT.Cells[r, c].Text;
}
dt.Rows.Add(dr);
}
objWB.Close();
objXL.Quit();
return dt;
}
public static void ExportToExcel( DataTable tbl, string excelFilePath = null)
{
try
{
if (tbl == null || tbl.Columns.Count == 0)
throw new Exception("ExportToExcel: Null or empty input table!\n");
// load excel, and create a new workbook
var excelApp = new Excel.Application();
excelApp.Workbooks.Add();
// single worksheet
Excel._Worksheet workSheet = excelApp.ActiveSheet;
// column headings
for (var i = 0; i < tbl.Columns.Count; i++)
{
workSheet.Cells[1, i + 1] = tbl.Columns[i].ColumnName;
}
// rows
for (var i = 0; i < tbl.Rows.Count; i++)
{
// to do: format datetime values before printing
for (var j = 0; j < tbl.Columns.Count; j++)
{
workSheet.Cells[i + 2, j + 1] = tbl.Rows[i][j];
}
}
// check file path
if (!string.IsNullOrEmpty(excelFilePath))
{
try
{
workSheet.SaveAs(excelFilePath);
excelApp.Quit();
Console.WriteLine("Excel file saved!");
}
catch (Exception ex)
{
throw new Exception("ExportToExcel: Excel file could not be saved! Check filepath.\n"
+ ex.Message);
}
}
else
{ // no file path is given
excelApp.Visible = true;
}
}
catch (Exception ex)
{
throw new Exception("ExportToExcel: \n" + ex.Message);
}
}
}
Initial csv file.
The excel file:

Reading large Excel files with c# and get the indexes

I tried to use Microsoft.Office.Interop.Excel but it's too slow when it comes to reading large excel documents (it was taking over 5 minutes for me). I read that DocumentFormat.OpenXml is faster when it comes to reading large excel documents but in the documentation it doesn't appear that I can't store the columns and row indexes.
For now, I am also only interested in the first row to get the column headers and I will be reading the rest of the document after some logic. I haven't been able to find a way to read only a portion of the excel document. I want to do something similar to this:
int r = 1; //row index
int c = 1; //column index
while (xlRange.Cells[r,c] != null && xlRange.Cells[r, c].Value2 != null)
{
TagListData.Add(new TagClass { IsTagSelected = false, TagName = xlRange[r, c].Value2.toString(), rIndex = r, cIndex = c });
c += 3;
}
Users will be picking excel documents through openFileDialog so there's no fixed number of rows of columns I can use. Is there a way I could make this work?
Thank you

In OpenXML if a cell has no text it might or might not appear in the list of cells (depends on whether it ever had text or not). Therefore the while (...Value2 != null) type of approach isn't really a safe way to do things in OpenXML.
Here is a very simple approach to reading the first row (written using LINQPad hence the Main and the Dump). Note the (simplified) use of the SharedStringTable to get the real text of the cell:
void Main()
{
var fileName = #"c:\temp\openxml-read-row.xlsx";
using (FileStream fs = new FileStream(fileName, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
{
using (SpreadsheetDocument doc = SpreadsheetDocument.Open(fs, false))
{
// Get the necessary bits of the doc
WorkbookPart workbookPart = doc.WorkbookPart;
SharedStringTablePart sstpart = workbookPart.GetPartsOfType<SharedStringTablePart>().First();
SharedStringTable sst = sstpart.SharedStringTable;
WorkbookStylesPart ssp = workbookPart.GetPartsOfType<WorkbookStylesPart>().First();
Stylesheet ss = ssp.Stylesheet;
// Get the first worksheet
WorksheetPart worksheetPart = workbookPart.WorksheetParts.First();
Worksheet sheet = worksheetPart.Worksheet;
var rows = sheet.Descendants<Row>();
var row = rows.First();
foreach (var cell in row.Descendants<Cell>())
{
var txt = GetCellText(cell, sst);
// LINQPad specific method .Dump()
$"{cell.CellReference} = {txt}".Dump();
}
}
}
}
// Very basic way to get the text of a cell
private string GetCellText(Cell cell, SharedStringTable sst)
{
if (cell == null)
return "";
if ((cell.DataType != null) && (cell.DataType == CellValues.SharedString))
{
int ssid = int.Parse(cell.CellValue.Text);
string str = sst.ChildElements[ssid].InnerText;
return str;
}
else if (cell.CellValue != null)
{
return cell.CellValue.Text;
}
return "";
}
However... there's potentially a lot of work involved with OpenXML and you'd be well advised to try and use something like ClosedXML or EPPlus instead.
eg using ClosedXML
using (var workbook = new XLWorkbook(fileName))
{
var worksheet = workbook.Worksheets.First();
var row = worksheet.Row(1);
foreach (var cell in row.CellsUsed())
{
var txt = cell.Value.ToString();
// LINQPad specific method .Dump()
$"{cell.Address.ToString()} = {txt}".Dump();
}
}

How to Read the Uploaded Excel File using NPOI with out storing in the server or in the Project

My sample Code is below using the NPOI.dll. I can read the EXCEL File (i.e. Excel would be stored in the system like D:/Jamal/Test.xls. Then the dll is easily reading the content, but I need to read the uploaded Excel file without storing it in any place before.The HTTPPOSTEDFILEBASE excelfile has the value for the Excel file but I need to know how to read it using NPOI dlls
public List<string> SendInvitesExcelFile1(List<String> CorrectMailIDs,
ListInvites Invites, HttpPostedFileBase excelfile)
{
List<string> mailids = new List<string>();
//string filename = (excelfile.FileName).ToString();
HSSFWorkbook hssfwb;
// using (FileStream file = new FileStream(#"D:\test.xls", FileMode.Open, FileAccess.Read))
using (FileStream file = new FileStream(excelFile.FileName, FileMode.Open, FileAccess.Read))
{
hssfwb = new HSSFWorkbook(file);
}
Sheet sheet = hssfwb.GetSheet("sheet1");
for (int row = 0; row <= sheet.LastRowNum; row++)
{
if (sheet.GetRow(row) != null) //null is when the row only contains empty cells
{
mailids.Add(sheet.GetRow(row).GetCell(0).ToString());
}
}
return mailids;

I came across the same problem and I solved it using Inpustream. I am pasting the code for your reference.
[HttpPost]
public DataTable PostValues(HttpPostedFileBase file)
{
ISheet sheet;
string filename = Path.GetFileName(Server.MapPath(file.FileName));
var fileExt = Path.GetExtension(filename);
if (fileExt == ".xls")
{
HSSFWorkbook hssfwb = new HSSFWorkbook(file.InputStream);
sheet = hssfwb.GetSheetAt(0);
}
else
{
XSSFWorkbook hssfwb = new XSSFWorkbook(file.InputStream);
sheet = hssfwb.GetSheetAt(0);
}
DataTable table = new DataTable();
IRow headerRow = sheet.GetRow(0);
int cellCount = headerRow.LastCellNum;
for (int i = headerRow.FirstCellNum; i < cellCount; i++)
{
DataColumn column = new DataColumn(headerRow.GetCell(i).StringCellValue);
table.Columns.Add(column);
}
int rowCount = sheet.LastRowNum;
for (int i = (sheet.FirstRowNum); i < sheet.LastRowNum; i++)
{
IRow row = sheet.GetRow(i);
DataRow dataRow = table.NewRow();
for (int j = row.FirstCellNum; j < cellCount; j++)
{
if (row.GetCell(j) != null)
{
dataRow[j] = row.GetCell(j).ToString();
}
}
table.Rows.Add(dataRow);
}
return table;
}

You can use a MemoryStream as well, so you should be able to get the byte array repsonse and open the spreadsheet. I'm unsure if the WorkbookFactory will detect the file type from the MemoryStream, so you may need to instruct the users to use the format that you require.

Here is how I use a MemoryStream to return a xls from a dot net core controller without ever storing it as a file.
IWorkbook wb = new HSSFWorkbook();
//Edit workbook object here
MemoryStream m = new MemoryStream();
wb.Write(m);
var byteArray = m.ToArray();
return new FileContentResult(byteArray, "application/vnd.ms-excel");

We Keep Coding

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