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Excel doesn't close despite objects being released

So, I have a class that I wrote to handle opening excel files, however excel doesn't close even though I call the close function. This worked before I started using multiple workbooks so I presume that its something to do with that but I have no idea how to fix this. Any help appreciated!
This is the code:
public class ExcelReaderClass
{
public Excel.Application? excelApp = null; // create a null excell object that will later be used to store the reference to the open excel app
public Excel.Workbooks? excelBooks = null; // create a null object collection that will contain all workbooks
public Excel.Workbook? excelBook = null; // create a null object that will contain a workbook (excel file)
public Excel.Worksheet? curWorksheet = null; // create a null worksheet object that will contain the reference to the current worksheet that is open
public Excel.Range? curWorksheetRange = null; // create a range object that will contain the data from the currently open worksheet
// function that opens excel file and opens excel if it isnt already open
public void openExcelFile(string filePath) // filePath = filepath for the worksheet that is to be opened
{
if(excelApp == null) // if excel isnt open
{
excelApp = new Excel.Application(); // create a new instance of excel
excelApp.DisplayAlerts = false; // prevents "do you want to save" popups, which we want because we are only looking at files not changing them
excelBooks = excelApp.Workbooks; // create a new instance of workbook object collection
}
excelBook = excelBooks.Add(filePath); // add the workbook to the collection
}
// function that closes all instances of excel opened by this program
public void closeExcelFile(bool save, bool closeAll) // bool that controls whether only the worksheet is closed or the whole instance of excel
{
//excelBook.Save(); // save function not needed in this instance but might be useful later
GC.Collect();
GC.WaitForPendingFinalizers();
foreach (Excel.Workbook workbook in excelBooks)
{
workbook.Close(save, System.Reflection.Missing.Value, System.Reflection.Missing.Value); // close the workbook
NAR(workbook);
}
NAR(excelBooks); ; // release the workbook collection from Com
NAR(excelBook);
NAR(curWorksheet);
NAR(curWorksheetRange);
if (closeAll) // if close all is true, we want to close the excel instance too
{
excelApp.Quit(); // quit out of excel
NAR(excelApp); // release excel from Com
}
}
public List<object[,]> readExcelFile(string[] filePaths) //
{
List<object[,]> rangeList = new List<object[,]>(); // list of objects that will contain the data from the excel sheets
foreach (var filePath in filePaths) // for each file
{
openExcelFile(filePath); // open the file in excel
}
foreach (var workbook in excelBooks) // iterate through workbooks
{
var book = workbook as Excel.Workbook; // set book as a reference to the workbook
curWorksheet = book.Worksheets[1]; // set this variable to the first sheet in the workbook
curWorksheetRange = curWorksheet.UsedRange; // set this variable to the workbook range
object[,]? range = (object[,])curWorksheetRange.Value2;
rangeList.Add(range);
}
closeExcelFile(false,true);
return (rangeList);
}
//function to kill object and release it from COM
private void NAR(object o)
{
try
{
Marshal.FinalReleaseComObject(o);
}
catch { }
finally
{
o = null;
}
}
}
I've tried using GC.Collect() and GC.WaitForPendingFinalizers() but that doesn't seem to work either.

Update, this is what I did to fix the code. Feel free to use it. (Doesn't work in Debug mode though)
public class ExcelReaderClass
{
public Excel.Application? excelApp = null; // create a null excell object that will later be used to store the reference to the open excel app
public Excel.Workbooks? excelBooks = null; // create a null object collection that will contain all workbooks
public Excel.Workbook? excelBook = null; // create a null object that will contain a workbook (excel file)
public Excel.Worksheet? curWorksheet = null; // create a null worksheet object that will contain the reference to the current worksheet that is open
public Excel.Range? curWorksheetRange = null; // create a range object that will contain the data from the currently open worksheet
// function that opens excel file and opens excel if it isnt already open
public void openExcelFile(string filePath) // filePath = filepath for the worksheet that is to be opened
{
if(excelApp == null) // if excel isnt open
{
excelApp = new Excel.Application(); // create a new instance of excel
excelApp.DisplayAlerts = false; // prevents "do you want to save" popups, which we want because we are only looking at files not changing them
excelBooks = excelApp.Workbooks; // create a new instance of workbook object collection
}
excelBook = excelBooks.Add(filePath); // add the workbook to the collection
}
// function that closes all instances of excel opened by this program
public void closeExcelFile(bool save, bool closeAll) // bool that controls whether only the worksheet is closed or the whole instance of excel
{
foreach (Excel.Workbook workbook in excelBooks)
{
workbook.Close(save, System.Reflection.Missing.Value, System.Reflection.Missing.Value); // close the workbook
}
excelBooks = null; // clear the reference to the workbook collection
excelBook = null; // clear the reference to the active workbook
curWorksheet = null; // clear the reference to the current worksheet
curWorksheetRange = null; // clear the reference to the range of the current worksheet
if (closeAll) // if close all is true, we want to close the excel instance too
{
excelApp.Quit(); // quit out of excel
excelApp = null;
}
}
public List<object[,]> readExcelFile(string[] filePaths)
{
List<object[,]> rangeList = new List<object[,]>();
foreach (var filePath in filePaths)
{
openExcelFile(filePath);
}
Console.WriteLine();
foreach (var workbook in excelBooks) // done to select the first workbook because other methods have failed but this works
{
var book = workbook as Excel.Workbook; // set book as a reference to the workbook
curWorksheet = book.Worksheets[1]; // set this variable to the first sheet in the workbook
curWorksheetRange = curWorksheet.UsedRange; // set this variable to the workbook range
object[,]? range = (object[,])curWorksheetRange.Value2;
rangeList.Add(range);
}
closeExcelFile(false,true);
GC.Collect();
GC.WaitForPendingFinalizers();
return (rangeList);
}
}
Quick Rundown:
I deleted the NAR function and any places it was called, added GC.Collect() and GC.WaitForPendingFinalisers after all my excel code is executed, and made sure all variables are set to null before GC.* functions are called.

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 copy templated sheet from excel file to active workbook

I'm writing a VSTO for excel. I have the following problem:
All this is going in the excel application
I need to programmatically add a new worksheet that must look the same as a template. I've got a template from which I can copy cells and formatting to the new added cell.
How can I do this?
I have tried the following way, to open an excel application making it invisible to user and opening the necessary template in that application. I'm going through the used range rows and trying to copy row by row. However, I encounter problems in opening the template. Once it gets opened, the other time it throws COM Exception(don't know what kind of that is).
var activeExcel = (Workbook)Globals.ThisAddIn.Application.ActiveWorkbook;
Sheet = (Worksheet) activeExcel.Worksheets.Add();
Sheet.Name = "Счёт-фактура";
var sourcePath = LocationHelperTool.GetTemplatePathByName("SystemInvoice.xlsx");
try
{
var excelApp = new Application() { Visible = false };
var workbook = excelApp.Workbooks.Open(sourcePath);
var workSheets = workbook.Worksheets;
const string sourceSheetName = "Счёт-фактура";
var sourceSheet = (Worksheet)workSheets.Item[sourceSheetName];
var sourceRange = sourceSheet.UsedRange;
for (var i = 1; i <= sourceRange.Rows.Count; i++)
{
var soRange = sourceRange.Rows[i];
var deRange = Sheet.Rows[i];
soRange.Copy(Type.Missing);
deRange.pasteSpecial(XlPasteType.xlPasteFormats);
}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
finally
{
Clipboard.Clear();
excelApp.Quit();
}
I want to open a new sheet in the excel instance that the user is interacting and that sheet should be an exact clone of the template

The reason the code runs only once appears to be because the COM objects it instantiates are not being released - so they can't be re-used:
var excelApp = new Application() { Visible = false };
var workbook = excelApp.Workbooks.Open(sourcePath);
var workSheets = workbook.Worksheets;
const string sourceSheetName = "Счёт-фактура";
var sourceSheet = (Worksheet)workSheets.Item[sourceSheetName];
In the clean-up for this section of code you need something along these lines, where the objects are released in the reverse order they were instantiated (when the later depends on the earlier). Then the released objects need to be garbage-collected in order to ensure the code can no longer "see" them.
sourceRange = null;
soRange = null;
deRange = null;
workbook.Close(false); //do not save changes
sourceSheet = null;
workSheets = null;
workbook = null;
excelApp.Quit();
excelApp = null;
GC.Collect();
GC.AwaitPendingFinalizers();
GC.Collect();
GC.AwaitPendingFinalizers();

C# not creating the excel file and cannot write in different excel sheets

First of all in my code im opening an excel sheet and reading it into a list. Second of all im closing this excel sheet and creating a new excel sheet:
excel_init("C:\\Users\\oma\\Desktop\\excel2.xlsx"); // this path does NOT exist yet
Next its going to this method:
static void excel_init(String path)
{
appExcel = new Microsoft.Office.Interop.Excel.ApplicationClass();
if (System.IO.File.Exists(path))
{
// then go and load this into excel
newWorkbook_First = appExcel.Workbooks.Open(path, true, true);
objsheet = (_Worksheet)appExcel.ActiveWorkbook.ActiveSheet;
}
else
{
try
{
appExcel = new Microsoft.Office.Interop.Excel.ApplicationClass();
appExcel.Visible = true;
newWorkbook_First = appExcel.Workbooks.Add(1);
objsheet = (Microsoft.Office.Interop.Excel.Worksheet)newWorkbook_First.Sheets[1];
objsheet.Name = ("test");
var newSheet3 = (Microsoft.Office.Interop.Excel.Worksheet)appExcel.Worksheets.Add(Type.Missing, appExcel.Worksheets[appExcel.Worksheets.Count], 1, XlSheetType.xlWorksheet);
newSheet3.Name = "test2";
var newSheet2 = (Microsoft.Office.Interop.Excel.Worksheet)appExcel.Worksheets.Add(Type.Missing, appExcel.Worksheets[appExcel.Worksheets.Count], 1, XlSheetType.xlWorksheet);
newSheet2.Name = "test3";
}
catch (Exception e)
{
Console.Write("Error");
}
finally
{
}
}
}
It wont create excel2.xlsx on my desktop, why not?
Next in my main I am shouting excel_setValue this way:
excel_setValue("C", "hello", "");
This is the excel_setValue function:
static void excel_setValue(string cellname, string value, string color)
{
objsheet.get_Range(cellname).set_Value(Type.Missing, value);
if (kleur == "red")
{
objsheet.get_Range(cellname).Interior.Color = System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red);
}
}
How do I add the sheet to this? For exmaple: excel_setValue(cellname, value, color, sheetname)
Finally I do excel_close();
the excel_close function:
static void excel_close()
{
if (appExcel != null)
{
try
{
newWorkbook_First.Close();
System.Runtime.InteropServices.Marshal.ReleaseComObject(appExcel.ActiveWorkbook.ActiveSheet);
System.Runtime.InteropServices.Marshal.ReleaseComObject(appExcel.ActiveWorkbook);
System.Runtime.InteropServices.Marshal.ReleaseComObject(appExcel);
appExcel = null;
objsheet = null;
}
catch (Exception ex)
{
appExcel = null;
Console.WriteLine("Unable to release the Object " + ex.ToString());
}
finally
{
GC.Collect();
}
}
}
It closes and ask me if I wanna save/not-save or cancel it. And it will save # documents with no errors given

I create my Excel like this worked fine for me!
You need to do the folowing in you code before the newWorkbook_First.close(); part:
newWorkbook_First.SaveAs(totalPath);
I hope this will help you solve the problems..
using Excel = Microsoft.Office.Interop.Excel;
internal static bool ExportDGV(DataGridView DGV, List<string> selectedCustomerList, string path, string fileName, string exportName, int exportType, string mailSubject)
{
string totalPath;
//Create an Excel application instance
Excel.Application excelApp = new Excel.Application();
Excel.Workbook excelWorkBook = excelApp.Application.Workbooks.Add();
Excel._Worksheet worksheet = null;
excelApp.Visible = false;
worksheet = excelWorkBook.ActiveSheet;
//set headers
for (int i = 1; i < DataGridView.Columns.Count + 1; i++)
{
worksheet.Cells[1, i] = DGV.Columns[i - 1].HeaderText;
}
createList(worksheet, DGV);
//Create excel with the choosen name
Worksheet sheet1 = excelWorkBook.Worksheets[1];
worksheet.Name = fileName;
totalPath = path + "/" + fileName + ".xlsx";
//if path exist add a number
totalPath = directoryExist(totalPath, path, fileName);
//Save exel and Quit exelApp
excelWorkBook.SaveAs(totalPath);
excelWorkBook.Close();
excelApp.Quit();
}

You can use EpPlus library for excel. It is very easy to use and well documented. You don't need to use COM classes anymore

How to access an already opened Excel file in C#?

I have an excel workbook opened via double-clicking it in windows explorer but cannot access it in code
Excel.Application xlApp = (Application)Marshal.GetActiveObject("Excel.Application");
Excel.Workbooks xlBooks = xlApp.Workbooks;
xlBooks.Count equals 0, why isn't it referencing my opened workbook?
EDIT
Here are the various scenarios and what is happening:
Scenario 1: If the file is not already open
Code opens workbook, I am happy.
Scenario 2: If the file is initially opened from code and I close and reopen the app
Code references file just fine xlBooks.Count equals 1, I am happy.
Scenario 3: If the file is initially opened not from code, and via double-clicking it in explorer
Code opens another instance of the file xlBooks.Count equals 0, I am in a rage!
Here is the entire code as it stands right now
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices;
using Microsoft.Office.Interop.Excel;
public class ExcelService : IExcelService
{
const string _filePath = #"C:\Somewhere";
const string _fileName = #"TestFile.xlsb";
string _fileNameAndPath = Path.Combine(_filePath, _fileName);
Application xlApp;
Workbooks xlBooks;
Workbook xlBook;
Worksheet xlSheet;
public ExcelService()
{
try
{
xlApp = (Application)Marshal.GetActiveObject("Excel.Application");
xlBooks = xlApp.Workbooks;
var numBooks = xlBooks.Count;
Log.Info("Number of workbooks: {0}".FormatWith(numBooks));
if (numBooks > 0)
{
xlBook = xlBooks[1];
Log.Info("Using already opened workbook");
}
else
{
xlBook = xlBooks.Open(_fileNameAndPath);
Log.Info("Opening workbook: {0}".FormatWith(_fileNameAndPath));
}
xlSheet = (Worksheet)xlBook.Worksheets[1];
// test reading a named range
string value = xlSheet.Range["TEST"].Value.ToString();
Log.Info(#"TEST: {0}".FormatWith(value));
xlApp.Visible = true;
}
catch (Exception e)
{
Log.Error(e.Message);
}
}
~ExcelService()
{
GC.Collect();
GC.WaitForPendingFinalizers();
try
{
Marshal.FinalReleaseComObject(xlSheet);
}
catch { }
try
{
Marshal.FinalReleaseComObject(xlBook);
}
catch { }
try
{
Marshal.FinalReleaseComObject(xlBooks);
}
catch { }
try
{
Marshal.FinalReleaseComObject(xlApp);
}
catch { }
}
}

I know this thread is a little old, but I found another way of doing this. When you create a new Excel.Applicationobject you have to create the WorkBooks object. When you access an already opened Excel file, the WorkBooks object is already created, so you just need to add a new WorkBook to the existing one. #Tipx 's solution works great if you have access to the WorkBook name, but in my case the current WorkBook name is always random. Here's the solution I came up with to get around this:
Excel.Application excelApp = null;
Excel.Workbooks wkbks = null;
Excel.Workbook wkbk = null;
bool wasFoundRunning = false;
Excel.Application tApp = null;
//Checks to see if excel is opened
try
{
tApp = (Excel.Application)System.Runtime.InteropServices.Marshal.GetActiveObject("Excel.Application");
wasFoundRunning = true;
}
catch (Exception)//Excel not open
{
wasFoundRunning = false;
}
finally
{
if (true == wasFoundRunning)
{
excelApp = tApp;
wkbk = excelApp.Workbooks.Add(Type.Missing);
}
else
{
excelApp = new Excel.Application();
wkbks = excelApp.Workbooks;
wkbk = wkbks.Add(Type.Missing);
}
//Release the temp if in use
if (null != tApp) { Marshal.FinalReleaseComObject(tApp); }
tApp = null;
}
//Initialize the sheets in the new workbook
Might not be the best solution but it worked for my needs. Hope this helps someone. :)

If all your workbooks are opened in the same Excel instance (you can check this by checking if you can switch from one to the other using Alt-tab). You can simply refer to the other using Workbooks("[FileName]"). So, for example :
Dim wb as Workbook //for C#, type Excel.Workbook wb = null;
Set wb = Workbooks("MyDuperWorkbook.xlsx") //for C#, type wb = Excel.Workbooks["MyDuperWorkbook.xlsx"];
wb.Sheets(1).Cells(1,1).Value = "Wahou!"