How do I create an Excel (.XLS and .XLSX) file in C# without installing Microsoft Office?

Question

How can I create an Excel spreadsheet with C# without requiring Excel to be installed on the machine that's running the code?

@Mike The "without requiring Excel to be installed" piece has nothing to do with being professional. It's about dependencies. The original text of the question was worded as: "Ideally, I would like open source so I don't have to add any third party dependencies to my code, and I would like to avoid using Excel directly to create the file (using OLE Automation.)" It's unfortunate the question was drastically simplified. — Tony, Commented Apr 2, 2019 at 15:02
Assuming you were trying to do something sans library or external code, I can't speak for xls file, but for xlsx files, why not start by taking an existing one, renaming it to a zip file and exploring the contents? A little bit of reverse engineering will tell you quite a bit. There are several different xml files and rels files in the various folders and subfolders. Try exploring that and see if it's something you can replicate or see if you can find documentation on the various xml namespaces/schemas. — Alexander Ryan Baggett, Commented Aug 13, 2019 at 21:37

2 revs, 2 users 50% · Accepted Answer · 2018-07-18 06:19:44Z

6

You can just write it out to XML using the Excel XML format and name it with .XLS extension and it will open with excel. You can control all the formatting (bold, widths, etc) in your XML file heading.

There is an example XML from Wikipedia.

edited Jul 18, 2018 at 6:19

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2 revs, 2 users 50%
ScaleOvenStove

When I try to rename it to xls, I got this warning message: The file format and extension of 'XXx.xls' don't match. The file could be corrupted or unsafe. Unless you trust its source, don't open it. Do you want to open it anyway?
– enb141
Commented Mar 24, 2023 at 6:42

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Fabian · Accepted Answer · 2022-09-30 16:05:26Z

6

I found another library that does it without much dependencies: MiniExcel.

You can create a DataSet with DataTables as spreadsheets (the name of the table being the name of the spreadsheet) and save it to .xlsx file by

using var stream = File.Create(filePath);
stream.SaveAs(dataSet);

or

MiniExcel.SaveAs(filePath, dataSet);

It offers also reading of Excel files and does support reading and writing of CSV files.

answered Sep 30, 2022 at 16:05

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Fabian

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2 revs, 2 users 93% anon · Accepted Answer · 2018-07-18 06:17:49Z

5

I also vote for GemBox.Spreadsheet.

Very fast and easy to use, with tons of examples on their site.

Took my reporting tasks on a whole new level of execution speed.

edited Jul 18, 2018 at 6:17

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2 revs, 2 users 93%
anon

Free version limited: Maximum number of rows per sheet is 150.
– Kiquenet
Commented Dec 11, 2020 at 15:43

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2 revs, 2 users 95% · Accepted Answer · 2018-07-18 06:20:44Z

One really easy option which is often overlooked is to create a .rdlc report using Microsoft Reporting and export it to excel format. You can design it in visual studio and generate the file using:

localReport.Render("EXCELOPENXML", null, ((name, ext, encoding, mimeType, willSeek) => stream = new FileStream(name, FileMode.CreateNew)), out warnings);

You can also export it do .doc or .pdf, using "WORDOPENXML" and "PDF" respectively, and it's supported on many different platforms such as ASP.NET and SSRS.

It's much easier to make changes in a visual designer where you can see the results, and trust me, once you start grouping data, formatting group headers, adding new sections, you don't want to mess with dozens of XML nodes.

full source code sample ? rdlc issues memory in ASP.NET travis.io/blog/2014/10/27/rdlc-performance-issues-dotnet45 and stackoverflow.com/questions/33436607/… — Kiquenet, Commented Dec 11, 2020 at 15:46

2 revs, 2 users 97% · Accepted Answer · 2019-12-21 06:09:40Z

5

You can try my SwiftExcel library. This library writes directly to the file, so it is very efficient. For example you can write 100k rows in few seconds without any memory usage.

Here is a simple example of usage:

using (var ew = new ExcelWriter("C:\\temp\\test.xlsx"))
{
    for (var row = 1; row <= 10; row++)
    {
        for (var col = 1; col <= 5; col++)
        {
            ew.Write($"row:{row}-col:{col}", col, row);
        }
    }
}

edited Dec 21, 2019 at 6:09

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2 revs, 2 users 97%
Roman.Pavelko

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3 revs · Accepted Answer · 2022-01-20 10:32:26Z

Here is the simplest way to create an Excel file.

Excel files with extension .xlsx are compressed folders containing .XML files - but complicated.

First create the folder structure as follows -

public class CreateFileOrFolder
{
    static void Main()
    {
        //
        // https://learn.microsoft.com/en-us/dotnet/csharp/programming-guide/file-system/how-to-create-a-file-or-folder
        //
        // https://learn.microsoft.com/en-us/dotnet/csharp/programming-guide/file-system/how-to-write-to-a-text-file
        //
        // .NET Framework 4.7.2
        //
        // Specify a name for your top-level folder.
        string folderName = @"C:\Users\david\Desktop\Book3";

        // To create a string that specifies the path to a subfolder under your
        // top-level folder, add a name for the subfolder to folderName.

        string pathString = System.IO.Path.Combine(folderName, "_rels");
        System.IO.Directory.CreateDirectory(pathString);
        pathString = System.IO.Path.Combine(folderName, "docProps");
        System.IO.Directory.CreateDirectory(pathString);
        pathString = System.IO.Path.Combine(folderName, "xl");
        System.IO.Directory.CreateDirectory(pathString);

        string subPathString = System.IO.Path.Combine(pathString, "_rels");
        System.IO.Directory.CreateDirectory(subPathString);
        subPathString = System.IO.Path.Combine(pathString, "theme");
        System.IO.Directory.CreateDirectory(subPathString);
        subPathString = System.IO.Path.Combine(pathString, "worksheets");
        System.IO.Directory.CreateDirectory(subPathString);
        // Keep the console window open in debug mode.
        System.Console.WriteLine("Press any key to exit.");
        System.Console.ReadKey();
    }
}

Next, create text files to hold the XML needed to describe the Excel spreadsheet.

namespace MakeFiles3
{
    class Program
    {
        static void Main(string[] args)
        {
            //
            // https://learn.microsoft.com/en-us/dotnet/csharp/programming-guide/file-system/how-to-write-to-a-text-file
            //
            // .NET Framework 4.7.2
            //
            string fileName = @"C:\Users\david\Desktop\Book3\_rels\.rels";
            fnWriteFile(fileName);
            fileName = @"C:\Users\david\Desktop\Book3\docProps\app.xml";
            fnWriteFile(fileName);
            fileName = @"C:\Users\david\Desktop\Book3\docProps\core.xml";
            fnWriteFile(fileName);
            fileName = @"C:\Users\david\Desktop\Book3\xl\_rels\workbook.xml.rels";
            fnWriteFile(fileName);
            fileName = @"C:\Users\david\Desktop\Book3\xl\theme\theme1.xml";
            fnWriteFile(fileName);
            fileName = @"C:\Users\david\Desktop\Book3\xl\worksheets\sheet1.xml";
            fnWriteFile(fileName);
            fileName = @"C:\Users\david\Desktop\Book3\xl\styles.xml";
            fnWriteFile(fileName);
            fileName = @"C:\Users\david\Desktop\Book3\xl\workbook.xml";
            fnWriteFile(fileName);
            fileName = @"C:\Users\david\Desktop\Book3\[Content_Types].xml";
            fnWriteFile(fileName);
            // Keep the console window open in debug mode.
            System.Console.WriteLine("Press any key to exit.");
            System.Console.ReadKey();

            bool fnWriteFile(string strFilePath)
            {
                if (!System.IO.File.Exists(strFilePath))
                {
                    using (System.IO.FileStream fs = System.IO.File.Create(strFilePath))
                    {
                        return true;
                    }
                }
                else
                {
                    System.Console.WriteLine("File \"{0}\" already exists.", strFilePath);
                    return false;
                }
            }
        }
    }
}

Next populate the text files with XML.

The XML required is fairly verbose so you may need to use this github repository.

https://github.com/DaveTallett26/MakeFiles4/blob/master/MakeFiles4/Program.cs

//
// https://learn.microsoft.com/en-us/dotnet/standard/io/how-to-write-text-to-a-file
// .NET Framework 4.7.2
//
using System.IO;

namespace MakeFiles4
{
    class Program
    {
        static void Main(string[] args)
        {
            string xContents = @"a";
            string xFilename = @"a";
            xFilename = @"C:\Users\david\Desktop\Book3\[Content_Types].xml";
            xContents = @"<?xml version=""1.0"" encoding=""UTF-8"" standalone=""yes""?><Types xmlns=""http://schemas.openxmlformats.org/package/2006/content-types""><Default Extension=""rels"" ContentType=""application/vnd.openxmlformats-package.relationships+xml""/><Default Extension=""xml"" ContentType=""application/xml""/><Override PartName=""/xl/workbook.xml"" ContentType=""application/vnd.openxmlformats-officedocument.spreadsheetml.sheet.main+xml""/><Override PartName=""/xl/worksheets/sheet1.xml"" ContentType=""application/vnd.openxmlformats-officedocument.spreadsheetml.worksheet+xml""/><Override PartName=""/xl/theme/theme1.xml"" ContentType=""application/vnd.openxmlformats-officedocument.theme+xml""/><Override PartName=""/xl/styles.xml"" ContentType=""application/vnd.openxmlformats-officedocument.spreadsheetml.styles+xml""/><Override PartName=""/docProps/core.xml"" ContentType=""application/vnd.openxmlformats-package.core-properties+xml""/><Override PartName=""/docProps/app.xml"" ContentType=""application/vnd.openxmlformats-officedocument.extended-properties+xml""/></Types>";
            StartExstream(xContents, xFilename);

            xFilename = @"C:\Users\david\Desktop\Book3\_rels\.rels";
            xContents = @"<?xml version=""1.0"" encoding=""UTF-8"" standalone=""yes""?><Relationships xmlns=""http://schemas.openxmlformats.org/package/2006/relationships""><Relationship Id=""rId3"" Type=""http://schemas.openxmlformats.org/officeDocument/2006/relationships/extended-properties"" Target=""docProps/app.xml""/><Relationship Id=""rId2"" Type=""http://schemas.openxmlformats.org/package/2006/relationships/metadata/core-properties"" Target=""docProps/core.xml""/><Relationship Id=""rId1"" Type=""http://schemas.openxmlformats.org/officeDocument/2006/relationships/officeDocument"" Target=""xl/workbook.xml""/></Relationships>";
            StartExstream(xContents, xFilename);

            xFilename = @"C:\Users\david\Desktop\Book3\docProps\app.xml";
            xContents = @"<?xml version=""1.0"" encoding=""UTF-8"" standalone=""yes""?><Properties xmlns=""http://schemas.openxmlformats.org/officeDocument/2006/extended-properties"" xmlns:vt=""http://schemas.openxmlformats.org/officeDocument/2006/docPropsVTypes""><Application>Microsoft Excel</Application><DocSecurity>0</DocSecurity><ScaleCrop>false</ScaleCrop><HeadingPairs><vt:vector size=""2"" baseType=""variant""><vt:variant><vt:lpstr>Worksheets</vt:lpstr></vt:variant><vt:variant><vt:i4>1</vt:i4></vt:variant></vt:vector></HeadingPairs><TitlesOfParts><vt:vector size=""1"" baseType=""lpstr""><vt:lpstr>Sheet1</vt:lpstr></vt:vector></TitlesOfParts><Company></Company><LinksUpToDate>false</LinksUpToDate><SharedDoc>false</SharedDoc><HyperlinksChanged>false</HyperlinksChanged><AppVersion>16.0300</AppVersion></Properties>";
            StartExstream(xContents, xFilename);

            xFilename = @"C:\Users\david\Desktop\Book3\docProps\core.xml";
            xContents = @"<?xml version=""1.0"" encoding=""UTF-8"" standalone=""yes""?><cp:coreProperties xmlns:cp=""http://schemas.openxmlformats.org/package/2006/metadata/core-properties"" xmlns:dc=""http://purl.org/dc/elements/1.1/"" xmlns:dcterms=""http://purl.org/dc/terms/"" xmlns:dcmitype=""http://purl.org/dc/dcmitype/"" xmlns:xsi=""http://www.w3.org/2001/XMLSchema-instance""><dc:creator>David Tallett</dc:creator><cp:lastModifiedBy>David Tallett</cp:lastModifiedBy><dcterms:created xsi:type=""dcterms:W3CDTF"">2021-10-26T15:47:15Z</dcterms:created><dcterms:modified xsi:type=""dcterms:W3CDTF"">2021-10-26T15:47:35Z</dcterms:modified></cp:coreProperties>";
            StartExstream(xContents, xFilename);

            xFilename = @"C:\Users\david\Desktop\Book3\xl\styles.xml";
            xContents = @"<?xml version=""1.0"" encoding=""UTF-8"" standalone=""yes""?><styleSheet xmlns=""http://schemas.openxmlformats.org/spreadsheetml/2006/main"" xmlns:mc=""http://schemas.openxmlformats.org/markup-compatibility/2006"" mc:Ignorable=""x14ac x16r2 xr"" xmlns:x14ac=""http://schemas.microsoft.com/office/spreadsheetml/2009/9/ac"" xmlns:x16r2=""http://schemas.microsoft.com/office/spreadsheetml/2015/02/main"" xmlns:xr=""http://schemas.microsoft.com/office/spreadsheetml/2014/revision""><fonts count=""1"" x14ac:knownFonts=""1""><font><sz val=""11""/><color theme=""1""/><name val=""Calibri""/><family val=""2""/><scheme val=""minor""/></font></fonts><fills count=""2""><fill><patternFill patternType=""none""/></fill><fill><patternFill patternType=""gray125""/></fill></fills><borders count=""1""><border><left/><right/><top/><bottom/><diagonal/></border></borders><cellStyleXfs count=""1""><xf numFmtId=""0"" fontId=""0"" fillId=""0"" borderId=""0""/></cellStyleXfs><cellXfs count=""1""><xf numFmtId=""0"" fontId=""0"" fillId=""0"" borderId=""0"" xfId=""0""/></cellXfs><cellStyles count=""1""><cellStyle name=""Normal"" xfId=""0"" builtinId=""0""/></cellStyles><dxfs count=""0""/><tableStyles count=""0"" defaultTableStyle=""TableStyleMedium2"" defaultPivotStyle=""PivotStyleLight16""/><extLst><ext uri=""{EB79DEF2-80B8-43e5-95BD-54CBDDF9020C}"" xmlns:x14=""http://schemas.microsoft.com/office/spreadsheetml/2009/9/main""><x14:slicerStyles defaultSlicerStyle=""SlicerStyleLight1""/></ext><ext uri=""{9260A510-F301-46a8-8635-F512D64BE5F5}"" xmlns:x15=""http://schemas.microsoft.com/office/spreadsheetml/2010/11/main""><x15:timelineStyles defaultTimelineStyle=""TimeSlicerStyleLight1""/></ext></extLst></styleSheet>";
            StartExstream(xContents, xFilename);

            xFilename = @"C:\Users\david\Desktop\Book3\xl\workbook.xml";
            xContents = @"<?xml version=""1.0"" encoding=""UTF-8"" standalone=""yes""?><workbook xmlns=""http://schemas.openxmlformats.org/spreadsheetml/2006/main"" xmlns:r=""http://schemas.openxmlformats.org/officeDocument/2006/relationships"" xmlns:mc=""http://schemas.openxmlformats.org/markup-compatibility/2006"" mc:Ignorable=""x15 xr xr6 xr10 xr2"" xmlns:x15=""http://schemas.microsoft.com/office/spreadsheetml/2010/11/main"" xmlns:xr=""http://schemas.microsoft.com/office/spreadsheetml/2014/revision"" xmlns:xr6=""http://schemas.microsoft.com/office/spreadsheetml/2016/revision6"" xmlns:xr10=""http://schemas.microsoft.com/office/spreadsheetml/2016/revision10"" xmlns:xr2=""http://schemas.microsoft.com/office/spreadsheetml/2015/revision2""><fileVersion appName=""xl"" lastEdited=""7"" lowestEdited=""7"" rupBuild=""24430""/><workbookPr defaultThemeVersion=""166925""/><mc:AlternateContent xmlns:mc=""http://schemas.openxmlformats.org/markup-compatibility/2006""><mc:Choice Requires=""x15""><x15ac:absPath url=""C:\Users\david\Desktop\"" xmlns:x15ac=""http://schemas.microsoft.com/office/spreadsheetml/2010/11/ac""/></mc:Choice></mc:AlternateContent><xr:revisionPtr revIDLastSave=""0"" documentId=""8_{C633700D-2D40-49EE-8C5E-2561E28A6758}"" xr6:coauthVersionLast=""47"" xr6:coauthVersionMax=""47"" xr10:uidLastSave=""{00000000-0000-0000-0000-000000000000}""/><bookViews><workbookView xWindow=""-120"" yWindow=""-120"" windowWidth=""29040"" windowHeight=""15840"" xr2:uid=""{934C5B62-1DC1-4322-BAE8-00D615BD2FB3}""/></bookViews><sheets><sheet name=""Sheet1"" sheetId=""1"" r:id=""rId1""/></sheets><calcPr calcId=""191029""/><extLst><ext uri=""{140A7094-0E35-4892-8432-C4D2E57EDEB5}"" xmlns:x15=""http://schemas.microsoft.com/office/spreadsheetml/2010/11/main""><x15:workbookPr chartTrackingRefBase=""1""/></ext><ext uri=""{B58B0392-4F1F-4190-BB64-5DF3571DCE5F}"" xmlns:xcalcf=""http://schemas.microsoft.com/office/spreadsheetml/2018/calcfeatures""><xcalcf:calcFeatures><xcalcf:feature name=""microsoft.com:RD""/><xcalcf:feature name=""microsoft.com:Single""/><xcalcf:feature name=""microsoft.com:FV""/><xcalcf:feature name=""microsoft.com:CNMTM""/><xcalcf:feature name=""microsoft.com:LET_WF""/></xcalcf:calcFeatures></ext></extLst></workbook>";
            StartExstream(xContents, xFilename);

            xFilename = @"C:\Users\david\Desktop\Book3\xl\_rels\workbook.xml.rels";
            xContents = @"<?xml version=""1.0"" encoding=""UTF-8"" standalone=""yes""?><Relationships xmlns=""http://schemas.openxmlformats.org/package/2006/relationships""><Relationship Id=""rId3"" Type=""http://schemas.openxmlformats.org/officeDocument/2006/relationships/styles"" Target=""styles.xml""/><Relationship Id=""rId2"" Type=""http://schemas.openxmlformats.org/officeDocument/2006/relationships/theme"" Target=""theme/theme1.xml""/><Relationship Id=""rId1"" Type=""http://schemas.openxmlformats.org/officeDocument/2006/relationships/worksheet"" Target=""worksheets/sheet1.xml""/></Relationships>";
            StartExstream(xContents, xFilename);

            xFilename = @"C:\Users\david\Desktop\Book3\xl\theme\theme1.xml";
            xContents = @"<?xml version=""1.0"" encoding=""UTF-8"" standalone=""yes""?><a:theme xmlns:a=""http://schemas.openxmlformats.org/drawingml/2006/main"" name=""Office Theme""><a:themeElements><a:clrScheme name=""Office""><a:dk1><a:sysClr val=""windowText"" lastClr=""000000""/></a:dk1><a:lt1><a:sysClr val=""window"" lastClr=""FFFFFF""/></a:lt1><a:dk2><a:srgbClr val=""44546A""/></a:dk2><a:lt2><a:srgbClr val=""E7E6E6""/></a:lt2><a:accent1><a:srgbClr val=""4472C4""/></a:accent1><a:accent2><a:srgbClr val=""ED7D31""/></a:accent2><a:accent3><a:srgbClr val=""A5A5A5""/></a:accent3><a:accent4><a:srgbClr val=""FFC000""/></a:accent4><a:accent5><a:srgbClr val=""5B9BD5""/></a:accent5><a:accent6><a:srgbClr val=""70AD47""/></a:accent6><a:hlink><a:srgbClr val=""0563C1""/></a:hlink><a:folHlink><a:srgbClr val=""954F72""/></a:folHlink></a:clrScheme><a:fontScheme name=""Office""><a:majorFont><a:latin typeface=""Calibri Light"" panose=""020F0302020204030204""/><a:ea typeface=""""/><a:cs typeface=""""/><a:font script=""Jpan"" typeface=""游ゴシック Light""/><a:font script=""Hang"" typeface=""맑은 고딕""/><a:font script=""Hans"" typeface=""等线 Light""/><a:font script=""Hant"" typeface=""新細明體""/><a:font script=""Arab"" typeface=""Times New Roman""/><a:font script=""Hebr"" typeface=""Times New Roman""/><a:font script=""Thai"" typeface=""Tahoma""/><a:font script=""Ethi"" typeface=""Nyala""/><a:font script=""Beng"" typeface=""Vrinda""/><a:font script=""Gujr"" typeface=""Shruti""/><a:font script=""Khmr"" typeface=""MoolBoran""/><a:font script=""Knda"" typeface=""Tunga""/><a:font script=""Guru"" typeface=""Raavi""/><a:font script=""Cans"" typeface=""Euphemia""/><a:font script=""Cher"" typeface=""Plantagenet Cherokee""/><a:font script=""Yiii"" typeface=""Microsoft Yi Baiti""/><a:font script=""Tibt"" typeface=""Microsoft Himalaya""/><a:font script=""Thaa"" typeface=""MV Boli""/><a:font script=""Deva"" typeface=""Mangal""/><a:font script=""Telu"" typeface=""Gautami""/><a:font script=""Taml"" typeface=""Latha""/><a:font script=""Syrc"" typeface=""Estrangelo Edessa""/><a:font script=""Orya"" typeface=""Kalinga""/><a:font script=""Mlym"" typeface=""Kartika""/><a:font script=""Laoo"" typeface=""DokChampa""/><a:font script=""Sinh"" typeface=""Iskoola Pota""/><a:font script=""Mong"" typeface=""Mongolian Baiti""/><a:font script=""Viet"" typeface=""Times New Roman""/><a:font script=""Uigh"" typeface=""Microsoft Uighur""/><a:font script=""Geor"" typeface=""Sylfaen""/><a:font script=""Armn"" typeface=""Arial""/><a:font script=""Bugi"" typeface=""Leelawadee UI""/><a:font script=""Bopo"" typeface=""Microsoft JhengHei""/><a:font script=""Java"" typeface=""Javanese Text""/><a:font script=""Lisu"" typeface=""Segoe UI""/><a:font script=""Mymr"" typeface=""Myanmar Text""/><a:font script=""Nkoo"" typeface=""Ebrima""/><a:font script=""Olck"" typeface=""Nirmala UI""/><a:font script=""Osma"" typeface=""Ebrima""/><a:font script=""Phag"" typeface=""Phagspa""/><a:font script=""Syrn"" typeface=""Estrangelo Edessa""/><a:font script=""Syrj"" typeface=""Estrangelo Edessa""/><a:font script=""Syre"" typeface=""Estrangelo Edessa""/><a:font script=""Sora"" typeface=""Nirmala UI""/><a:font script=""Tale"" typeface=""Microsoft Tai Le""/><a:font script=""Talu"" typeface=""Microsoft New Tai Lue""/><a:font script=""Tfng"" typeface=""Ebrima""/></a:majorFont><a:minorFont><a:latin typeface=""Calibri"" panose=""020F0502020204030204""/><a:ea typeface=""""/><a:cs typeface=""""/><a:font script=""Jpan"" typeface=""游ゴシック""/><a:font script=""Hang"" typeface=""맑은 고딕""/><a:font script=""Hans"" typeface=""等线""/><a:font script=""Hant"" typeface=""新細明體""/><a:font script=""Arab"" typeface=""Arial""/><a:font script=""Hebr"" typeface=""Arial""/><a:font script=""Thai"" typeface=""Tahoma""/><a:font script=""Ethi"" typeface=""Nyala""/><a:font script=""Beng"" typeface=""Vrinda""/><a:font script=""Gujr"" typeface=""Shruti""/><a:font script=""Khmr"" typeface=""DaunPenh""/><a:font script=""Knda"" typeface=""Tunga""/><a:font script=""Guru"" typeface=""Raavi""/><a:font script=""Cans"" typeface=""Euphemia""/><a:font script=""Cher"" typeface=""Plantagenet Cherokee""/><a:font script=""Yiii"" typeface=""Microsoft Yi Baiti""/><a:font script=""Tibt"" typeface=""Microsoft Himalaya""/><a:font script=""Thaa"" typeface=""MV Boli""/><a:font script=""Deva"" typeface=""Mangal""/><a:font script=""Telu"" typeface=""Gautami""/><a:font script=""Taml"" typeface=""Latha""/><a:font script=""Syrc"" typeface=""Estrangelo Edessa""/><a:font script=""Orya"" typeface=""Kalinga""/><a:font script=""Mlym"" typeface=""Kartika""/><a:font script=""Laoo"" typeface=""DokChampa""/><a:font script=""Sinh"" typeface=""Iskoola Pota""/><a:font script=""Mong"" typeface=""Mongolian Baiti""/><a:font script=""Viet"" typeface=""Arial""/><a:font script=""Uigh"" typeface=""Microsoft Uighur""/><a:font script=""Geor"" typeface=""Sylfaen""/><a:font script=""Armn"" typeface=""Arial""/><a:font script=""Bugi"" typeface=""Leelawadee UI""/><a:font script=""Bopo"" typeface=""Microsoft JhengHei""/><a:font script=""Java"" typeface=""Javanese Text""/><a:font script=""Lisu"" typeface=""Segoe UI""/><a:font script=""Mymr"" typeface=""Myanmar Text""/><a:font script=""Nkoo"" typeface=""Ebrima""/><a:font script=""Olck"" typeface=""Nirmala UI""/><a:font script=""Osma"" typeface=""Ebrima""/><a:font script=""Phag"" typeface=""Phagspa""/><a:font script=""Syrn"" typeface=""Estrangelo Edessa""/><a:font script=""Syrj"" typeface=""Estrangelo Edessa""/><a:font script=""Syre"" typeface=""Estrangelo Edessa""/><a:font script=""Sora"" typeface=""Nirmala UI""/><a:font script=""Tale"" typeface=""Microsoft Tai Le""/><a:font script=""Talu"" typeface=""Microsoft New Tai Lue""/><a:font script=""Tfng"" typeface=""Ebrima""/></a:minorFont></a:fontScheme><a:fmtScheme name=""Office""><a:fillStyleLst><a:solidFill><a:schemeClr val=""phClr""/></a:solidFill><a:gradFill rotWithShape=""1""><a:gsLst><a:gs pos=""0""><a:schemeClr val=""phClr""><a:lumMod val=""110000""/><a:satMod val=""105000""/><a:tint val=""67000""/></a:schemeClr></a:gs><a:gs pos=""50000""><a:schemeClr val=""phClr""><a:lumMod val=""105000""/><a:satMod val=""103000""/><a:tint val=""73000""/></a:schemeClr></a:gs><a:gs pos=""100000""><a:schemeClr val=""phClr""><a:lumMod val=""105000""/><a:satMod val=""109000""/><a:tint val=""81000""/></a:schemeClr></a:gs></a:gsLst><a:lin ang=""5400000"" scaled=""0""/></a:gradFill><a:gradFill rotWithShape=""1""><a:gsLst><a:gs pos=""0""><a:schemeClr val=""phClr""><a:satMod val=""103000""/><a:lumMod val=""102000""/><a:tint val=""94000""/></a:schemeClr></a:gs><a:gs pos=""50000""><a:schemeClr val=""phClr""><a:satMod val=""110000""/><a:lumMod val=""100000""/><a:shade val=""100000""/></a:schemeClr></a:gs><a:gs pos=""100000""><a:schemeClr val=""phClr""><a:lumMod val=""99000""/><a:satMod val=""120000""/><a:shade val=""78000""/></a:schemeClr></a:gs></a:gsLst><a:lin ang=""5400000"" scaled=""0""/></a:gradFill></a:fillStyleLst><a:lnStyleLst><a:ln w=""6350"" cap=""flat"" cmpd=""sng"" algn=""ctr""><a:solidFill><a:schemeClr val=""phClr""/></a:solidFill><a:prstDash val=""solid""/><a:miter lim=""800000""/></a:ln><a:ln w=""12700"" cap=""flat"" cmpd=""sng"" algn=""ctr""><a:solidFill><a:schemeClr val=""phClr""/></a:solidFill><a:prstDash val=""solid""/><a:miter lim=""800000""/></a:ln><a:ln w=""19050"" cap=""flat"" cmpd=""sng"" algn=""ctr""><a:solidFill><a:schemeClr val=""phClr""/></a:solidFill><a:prstDash val=""solid""/><a:miter lim=""800000""/></a:ln></a:lnStyleLst><a:effectStyleLst><a:effectStyle><a:effectLst/></a:effectStyle><a:effectStyle><a:effectLst/></a:effectStyle><a:effectStyle><a:effectLst><a:outerShdw blurRad=""57150"" dist=""19050"" dir=""5400000"" algn=""ctr"" rotWithShape=""0""><a:srgbClr val=""000000""><a:alpha val=""63000""/></a:srgbClr></a:outerShdw></a:effectLst></a:effectStyle></a:effectStyleLst><a:bgFillStyleLst><a:solidFill><a:schemeClr val=""phClr""/></a:solidFill><a:solidFill><a:schemeClr val=""phClr""><a:tint val=""95000""/><a:satMod val=""170000""/></a:schemeClr></a:solidFill><a:gradFill rotWithShape=""1""><a:gsLst><a:gs pos=""0""><a:schemeClr val=""phClr""><a:tint val=""93000""/><a:satMod val=""150000""/><a:shade val=""98000""/><a:lumMod val=""102000""/></a:schemeClr></a:gs><a:gs pos=""50000""><a:schemeClr val=""phClr""><a:tint val=""98000""/><a:satMod val=""130000""/><a:shade val=""90000""/><a:lumMod val=""103000""/></a:schemeClr></a:gs><a:gs pos=""100000""><a:schemeClr val=""phClr""><a:shade val=""63000""/><a:satMod val=""120000""/></a:schemeClr></a:gs></a:gsLst><a:lin ang=""5400000"" scaled=""0""/></a:gradFill></a:bgFillStyleLst></a:fmtScheme></a:themeElements><a:objectDefaults/><a:extraClrSchemeLst/><a:extLst><a:ext uri=""{05A4C25C-085E-4340-85A3-A5531E510DB2}""><thm15:themeFamily xmlns:thm15=""http://schemas.microsoft.com/office/thememl/2012/main"" name=""Office Theme"" id=""{62F939B6-93AF-4DB8-9C6B-D6C7DFDC589F}"" vid=""{4A3C46E8-61CC-4603-A589-7422A47A8E4A}""/></a:ext></a:extLst></a:theme>";
            StartExstream(xContents, xFilename);

            xFilename = @"C:\Users\david\Desktop\Book3\xl\worksheets\sheet1.xml";
            xContents = @"<?xml version=""1.0"" encoding=""UTF-8"" standalone=""yes""?><worksheet xmlns=""http://schemas.openxmlformats.org/spreadsheetml/2006/main"" xmlns:r=""http://schemas.openxmlformats.org/officeDocument/2006/relationships"" xmlns:mc=""http://schemas.openxmlformats.org/markup-compatibility/2006"" mc:Ignorable=""x14ac xr xr2 xr3"" xmlns:x14ac=""http://schemas.microsoft.com/office/spreadsheetml/2009/9/ac"" xmlns:xr=""http://schemas.microsoft.com/office/spreadsheetml/2014/revision"" xmlns:xr2=""http://schemas.microsoft.com/office/spreadsheetml/2015/revision2"" xmlns:xr3=""http://schemas.microsoft.com/office/spreadsheetml/2016/revision3"" xr:uid=""{54E3D330-4E78-4755-89E0-1AADACAC4953}""><dimension ref=""A1:A3""/><sheetViews><sheetView tabSelected=""1"" workbookViewId=""0""><selection activeCell=""A4"" sqref=""A4""/></sheetView></sheetViews><sheetFormatPr defaultRowHeight=""15"" x14ac:dyDescent=""0.25""/><sheetData><row r=""1"" spans=""1:1"" x14ac:dyDescent=""0.25""><c r=""A1""><v>1</v></c></row><row r=""2"" spans=""1:1"" x14ac:dyDescent=""0.25""><c r=""A2""><v>2</v></c></row><row r=""3"" spans=""1:1"" x14ac:dyDescent=""0.25""><c r=""A3""><v>3</v></c></row></sheetData><pageMargins left=""0.7"" right=""0.7"" top=""0.75"" bottom=""0.75"" header=""0.3"" footer=""0.3""/></worksheet>";
            StartExstream(xContents, xFilename);

            // Keep the console window open in debug mode.
            System.Console.WriteLine("Press any key to exit.");
            System.Console.ReadKey();

            bool StartExstream(string strLine, string strFileName)
            {
                // Write the string to a file.
                using (StreamWriter outputFile = new StreamWriter(strFileName))
                {
                    outputFile.WriteLine(strLine);
                    return true;
                }
            }
        }
    }
}

Finally ZIP the folder structure containing the XML -

namespace ZipFolder
// .NET Framework 4.7.2
// https://stackoverflow.com/questions/15241889/i-didnt-find-zipfile-class-in-the-system-io-compression-namespace?answertab=votes#tab-top
{
    class Program
    {
        static void Main(string[] args)
        {
            string xlPath = @"C:\Users\david\Desktop\Book3.xlsx";
            string folderPath = @"C:\Users\david\Desktop\Book3";

            System.IO.Compression.ZipFile.CreateFromDirectory(folderPath, xlPath);

            // Keep the console window open in debug mode.
            System.Console.WriteLine("Press any key to exit.");
            System.Console.ReadKey();
        }
    }
}

This produces an Excel file named Book3.xlsx which is valid and opens cleanly in Excel 365 on Windows 11.

The result is a very simple Excel spreadsheet but you may need to reverse engineer a more complex version. Here is the code to unzip a .xlsx file.

namespace UnZipXL
// .NET Framework 4.7.2
// https://stackoverflow.com/questions/15241889/i-didnt-find-zipfile-class-in-the-system-io-compression-namespace?answertab=votes#tab-top
{
    class Program
    {
        static void Main(string[] args)
        {
            string XLPath = @"C:\Users\david\Desktop\Book2.xlsx";
            string extractPath = @"C:\Users\david\Desktop\extract";

            System.IO.Compression.ZipFile.ExtractToDirectory(XLPath, extractPath);

            // Keep the console window open in debug mode.
            System.Console.WriteLine("Press any key to exit.");
            System.Console.ReadKey();
        }
    }
}

Update:

Here is a code fragment to update the Excel file. This is very simple again.

//
// https://learn.microsoft.com/en-us/dotnet/standard/io/how-to-write-text-to-a-file
// .NET Framework 4.7.2
//
using System.IO;

namespace UpdateWorksheet5
{
    class Program
    {
        static void Main(string[] args)
        {
            string xContents = @"a";
            string xFilename = @"a";

            xFilename = @"C:\Users\david\Desktop\Book3\xl\worksheets\sheet1.xml";
            xContents = @"<?xml version=""1.0"" encoding=""UTF-8"" standalone=""yes""?><worksheet xmlns=""http://schemas.openxmlformats.org/spreadsheetml/2006/main"" xmlns:r=""http://schemas.openxmlformats.org/officeDocument/2006/relationships"" xmlns:mc=""http://schemas.openxmlformats.org/markup-compatibility/2006"" mc:Ignorable=""x14ac xr xr2 xr3"" xmlns:x14ac=""http://schemas.microsoft.com/office/spreadsheetml/2009/9/ac"" xmlns:xr=""http://schemas.microsoft.com/office/spreadsheetml/2014/revision"" xmlns:xr2=""http://schemas.microsoft.com/office/spreadsheetml/2015/revision2"" xmlns:xr3=""http://schemas.microsoft.com/office/spreadsheetml/2016/revision3"" xr:uid=""{54E3D330-4E78-4755-89E0-1AADACAC4953}""><dimension ref=""A1:A3""/><sheetViews><sheetView tabSelected=""1"" workbookViewId=""0""><selection activeCell=""A4"" sqref=""A4""/></sheetView></sheetViews><sheetFormatPr defaultRowHeight=""15"" x14ac:dyDescent=""0.25""/><sheetData><row r=""1"" spans=""1:1"" x14ac:dyDescent=""0.25""><c r=""A1""><v>1</v></c></row><row r=""2"" spans=""1:1"" x14ac:dyDescent=""0.25""><c r=""A2""><v>2</v></c></row><row r=""3"" spans=""1:1"" x14ac:dyDescent=""0.25""><c r=""A3""><v>3</v></c></row></sheetData><pageMargins left=""0.7"" right=""0.7"" top=""0.75"" bottom=""0.75"" header=""0.3"" footer=""0.3""/></worksheet>";
            xContents = xContents.Remove(941, 1).Insert(941, "0"); //  character to replace is at 942 => index 941
            StartExstream(xContents, xFilename);

            // Keep the console window open in debug mode.
            System.Console.WriteLine("Press any key to exit.");
            System.Console.ReadKey();

            bool StartExstream(string strLine, string strFileName)
            {
                // Write the string to a file.
                using (StreamWriter outputFile = new StreamWriter(strFileName))
                {
                    outputFile.WriteLine(strLine);
                    return true;
                }
            }
        }
    }
}

Update 2 - This code works almost unchanged except for the folder paths on a Mac. Using Microsoft Excel Online, .NET Framework 3.1, Visual Studio 2019 for Mac, MacOS Monterey 12.1.

That's the basics of the zip structure but it looks like you've only got hard-coded XML examples and that you're a long way from setting an individual cell value, say. It might be easier to start with one of the other libraries linked here that have solved all of that already. — Rup, Commented Nov 14, 2021 at 14:54
This is anything but simple. This is the worst-case scenario — Panagiotis Kanavos, Commented Nov 24, 2021 at 17:03
I didn't know that xlsx files are actually zipped folders with xml files :D thanks for the information! — Ozan Yasin Dogan, Commented Dec 6, 2021 at 23:19
Kudos for trying, but editing one value by string offset is nowhere near general enough to be useful to anyone. How would you write a function in this scheme that accepted a cell row and column and set that cell to a number? And how would you do the same for a string (which is more complicated IIRC!) — Rup, Commented Dec 25, 2021 at 23:51
Do you have a reference? How can one learn this information? — john k, Commented Dec 30, 2022 at 11:58

Craig Mc · Accepted Answer · 2011-02-09 10:39:33Z

3

http://www.codeproject.com/KB/cs/Excel_and_C_.aspx <= why not just use the built in power of windows, just install office on the server, any application that you install can be automated.

So much easier just use the native methods.

If it installed you can use it, this is the most awesome and under used feature in windows it was Dubbed COM back in the good old days, and it saves you tons of time and pain.

Or even easier just use the ref lib MS supplies - http://csharp.net-informations.com/excel/csharp-create-excel.htm

answered Feb 9, 2011 at 10:39

community wiki

Craig Mc

Why is the second way easier? Isn't it the same (adding the native object library to your project)? Do you need to have Excel installed to get this object library working?
– Slauma
Commented Feb 9, 2011 at 12:45
7

Microsoft does not recommend or support Office Automation from non-interactive applications such as ASP.NET. See support.microsoft.com/kb/257757
– TrueWill
Commented Feb 9, 2011 at 18:17
Excel is quite unreliable & slow when it comes to Automation.
– Leslie Godwin
Commented Jun 25, 2015 at 9:21

Add a comment |

Michael Mainer · Accepted Answer · 2019-12-05 21:14:52Z

How to create an Excel (.xslx) file using C# on OneDrive without installing Microsoft Office

The Microsoft Graph API provides File and Excel APIs for creating and modifying Excel files stored in OneDrive for both enterprise and consumer accounts. The Microsoft.Graph NuGet package provides many interfaces for working with the File and Excel APIs.

{
  Name = "myExcelFile.xslx",
  File = new Microsoft.Graph.File()
};

// Create an empty file in the user's OneDrive.
var excelWorkbookDriveItem = await graphClient.Me.Drive.Root.Children.Request().AddAsync(excelWorkbook);

// Add the contents of a template Excel file.
DriveItem excelDriveItem;
using (Stream ms = ResourceHelper.GetResourceAsStream(ResourceHelper.ExcelTestResource))
{
    //Upload content to the file. ExcelTestResource is an empty template Excel file.
    //https://graph.microsoft.io/en-us/docs/api-reference/v1.0/api/item_uploadcontent
    excelDriveItem = await graphClient.Me.Drive.Items[excelWorkbookDriveItem.Id].Content.Request().PutAsync<DriveItem>(ms);
}

At this point, you now have an Excel file created in the user (enterprise or consumer) or group's OneDrive. You can now use the Excel APIs to make changes to the Excel file without using Excel and without needing to understand the Excel XML format.

full sample? what is graphClient ? ResourceHelper? ExcelTestResource is an empty template Excel file ? — Kiquenet, Commented Dec 11, 2020 at 15:48
@Kiquenet graphClient is found in the Microsoft.Graph NuGet package. Yes, ExcelTestResource is an empty Excel file. ResourceHelper gets the empty Excel file stream. Here's a sample that uses the GraphServiceClient (graphClient in this example): github.com/microsoftgraph/dotnetcore-console-sample. There isn't an example of using the Excel API in it. — Michael Mainer, Commented Dec 12, 2020 at 17:11

2 revs, 2 users 99% · Accepted Answer · 2020-06-30 12:36:19Z

You can install OpenXml nuget package on Visual Studio. Here is a bit of code to export a data table to an excel file:

Imports DocumentFormat.OpenXml
Imports DocumentFormat.OpenXml.Packaging
Imports DocumentFormat.OpenXml.Spreadsheet

Public Class ExportExcelClass
    Public Sub New()

    End Sub

    Public Sub ExportDataTable(ByVal table As DataTable, ByVal exportFile As String)
        ' Create a spreadsheet document by supplying the filepath.
        ' By default, AutoSave = true, Editable = true, and Type = xlsx.
        Dim spreadsheetDocument As SpreadsheetDocument = spreadsheetDocument.Create(exportFile, SpreadsheetDocumentType.Workbook)

        ' Add a WorkbookPart to the document.
        Dim workbook As WorkbookPart = spreadsheetDocument.AddWorkbookPart
        workbook.Workbook = New Workbook

        ' Add a WorksheetPart to the WorkbookPart.
        Dim Worksheet As WorksheetPart = workbook.AddNewPart(Of WorksheetPart)()
        Worksheet.Worksheet = New Worksheet(New SheetData())

        ' Add Sheets to the Workbook.
        Dim sheets As Sheets = spreadsheetDocument.WorkbookPart.Workbook.AppendChild(Of Sheets)(New Sheets())

        Dim data As SheetData = Worksheet.Worksheet.GetFirstChild(Of SheetData)()
        Dim Header As Row = New Row()
        Header.RowIndex = CType(1, UInt32)

        For Each column As DataColumn In table.Columns
            Dim headerCell As Cell = createTextCell(table.Columns.IndexOf(column) + 1, 1, column.ColumnName)
            Header.AppendChild(headerCell)
        Next

        data.AppendChild(Header)

        Dim contentRow As DataRow
        For i As Integer = 0 To table.Rows.Count - 1
            contentRow = table.Rows(i)
            data.AppendChild(createContentRow(contentRow, i + 2))
        Next

    End Sub

    Private Function createTextCell(ByVal columnIndex As Integer, ByVal rowIndex As Integer, ByVal cellValue As Object) As Cell
        Dim cell As Cell = New Cell()
        cell.DataType = CellValues.InlineString

        cell.CellReference = getColumnName(columnIndex) + rowIndex.ToString

        Dim inlineString As InlineString = New InlineString()
        Dim t As Text = New Text()
        t.Text = cellValue.ToString()
        inlineString.AppendChild(t)
        cell.AppendChild(inlineString)
        Return cell
    End Function

    Private Function createContentRow(ByVal dataRow As DataRow, ByVal rowIndex As Integer) As Row
        Dim row As Row = New Row With {
            .rowIndex = CType(rowIndex, UInt32)
        }

        For i As Integer = 0 To dataRow.Table.Columns.Count - 1
            Dim dataCell As Cell = createTextCell(i + 1, rowIndex, dataRow(i))
            row.AppendChild(dataCell)
        Next

        Return row
    End Function

    Private Function getColumnName(ByVal columnIndex As Integer) As String
        Dim dividend As Integer = columnIndex
        Dim columnName As String = String.Empty
        Dim modifier As Integer

        While dividend > 0
            modifier = (dividend - 1) Mod 26
            columnName = Convert.ToChar(65 + modifier).ToString() & columnName
            dividend = CInt(((dividend - modifier) / 26))
        End While

        Return columnName
    End Function
End Class

spreadsheetDocument.Create will be SpreadsheetDocument.Create ? — Kiquenet, Commented Jan 30, 2021 at 8:30

Mauricio Kenny · Accepted Answer · 2020-12-08 20:25:16Z

I recode again the code and now you can create an .xls file, later you can convert to Excel 2003 Open XML Format.

private static void exportToExcel(DataSet source, string fileName)
    {
        // Documentacion en:
        // https://en.wikipedia.org/wiki/Microsoft_Office_XML_formats
        // https://answers.microsoft.com/en-us/msoffice/forum/all/how-to-save-office-ms-xml-as-xlsx-file/4a77dae5-6855-457d-8359-e7b537beb1db
        // https://riptutorial.com/es/openxml

        const string startExcelXML = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\r\n"+
                 "<?mso-application progid=\"Excel.Sheet\"?>\r\n" +
                 "<Workbook xmlns=\"urn:schemas-microsoft-com:office:spreadsheet\"\r\n" +
                 "xmlns:o=\"urn:schemas-microsoft-com:office:office\"\r\n " +
                 "xmlns:x=\"urn:schemas-microsoft-com:office:excel\"\r\n " +
                 "xmlns:ss=\"urn:schemas-microsoft-com:office:spreadsheet\"\r\n " +
                 "xmlns:html=\"http://www.w3.org/TR/REC-html40\">\r\n " +
                 "xmlns:html=\"https://www.w3.org/TR/html401/\">\r\n " +

                 "<DocumentProperties xmlns=\"urn:schemas-microsoft-com:office:office\">\r\n " +
                 "  <Version>16.00</Version>\r\n " +
                 "</DocumentProperties>\r\n " +
                 " <OfficeDocumentSettings xmlns=\"urn:schemas-microsoft-com:office:office\">\r\n " +
                 "  <AllowPNG/>\r\n " +
                 " </OfficeDocumentSettings>\r\n " +

                 " <ExcelWorkbook xmlns=\"urn:schemas-microsoft-com:office:excel\">\r\n " +
                 "  <WindowHeight>9750</WindowHeight>\r\n " +
                 "  <WindowWidth>24000</WindowWidth>\r\n " +
                 "  <WindowTopX>0</WindowTopX>\r\n " +
                 "  <WindowTopY>0</WindowTopY>\r\n " +
                 "  <RefModeR1C1/>\r\n " +
                 "  <ProtectStructure>False</ProtectStructure>\r\n " +
                 "  <ProtectWindows>False</ProtectWindows>\r\n " +
                 " </ExcelWorkbook>\r\n " +

                 "<Styles>\r\n " +
                 "<Style ss:ID=\"Default\" ss:Name=\"Normal\">\r\n " +
                 "<Alignment ss:Vertical=\"Bottom\"/>\r\n <Borders/>" +
                 "\r\n <Font/>\r\n <Interior/>\r\n <NumberFormat/>" +
                 "\r\n <Protection/>\r\n </Style>\r\n " +
                 "<Style ss:ID=\"BoldColumn\">\r\n <Font " +
                 "x:Family=\"Swiss\" ss:Bold=\"1\"/>\r\n </Style>\r\n " +
                 "<Style ss:ID=\"StringLiteral\">\r\n <NumberFormat" +
                 " ss:Format=\"@\"/>\r\n </Style>\r\n <Style " +
                 "ss:ID=\"Decimal\">\r\n <NumberFormat " +
                 "ss:Format=\"0.0000\"/>\r\n </Style>\r\n " +
                 "<Style ss:ID=\"Integer\">\r\n <NumberFormat/>" +
                 "ss:Format=\"0\"/>\r\n </Style>\r\n <Style " +
                 "ss:ID=\"DateLiteral\">\r\n <NumberFormat " +
                 "ss:Format=\"dd/mm/yyyy;@\"/>\r\n </Style>\r\n " +
                 "</Styles>\r\n ";
        System.IO.StreamWriter excelDoc = null;
        excelDoc = new System.IO.StreamWriter(fileName,false);

        int sheetCount = 1;
        excelDoc.Write(startExcelXML);
        foreach (DataTable table in source.Tables)
        {
            int rowCount = 0;
            excelDoc.Write("<Worksheet ss:Name=\"" + table.TableName + "\">");
            excelDoc.Write("<Table>");
            excelDoc.Write("<Row>");
            for (int x = 0; x < table.Columns.Count; x++)
            {
                excelDoc.Write("<Cell ss:StyleID=\"BoldColumn\"><Data ss:Type=\"String\">");
                excelDoc.Write(table.Columns[x].ColumnName);
                excelDoc.Write("</Data></Cell>");
            }
            excelDoc.Write("</Row>");
            foreach (DataRow x in table.Rows)
            {
                rowCount++;
                //if the number of rows is > 64000 create a new page to continue output
                if (rowCount == 1048576)
                {
                    rowCount = 0;
                    sheetCount++;
                    excelDoc.Write("</Table>");
                    excelDoc.Write(" </Worksheet>");
                    excelDoc.Write("<Worksheet ss:Name=\"" + table.TableName + "\">");
                    excelDoc.Write("<Table>");
                }
                excelDoc.Write("<Row>"); //ID=" + rowCount + "
                for (int y = 0; y < table.Columns.Count; y++)
                {
                    System.Type rowType;
                    rowType = x[y].GetType();
                    switch (rowType.ToString())
                    {
                        case "System.String":
                            string XMLstring = x[y].ToString();
                            XMLstring = XMLstring.Trim();
                            XMLstring = XMLstring.Replace("&", "&");
                            XMLstring = XMLstring.Replace(">", ">");
                            XMLstring = XMLstring.Replace("<", "<");
                            excelDoc.Write("<Cell ss:StyleID=\"StringLiteral\">" +
                                           "<Data ss:Type=\"String\">");
                            excelDoc.Write(XMLstring);
                            excelDoc.Write("</Data></Cell>");
                            break;
                        case "System.DateTime":
                            //Excel has a specific Date Format of YYYY-MM-DD followed by  
                            //the letter 'T' then hh:mm:sss.lll Example 2005-01-31T24:01:21.000
                            //The Following Code puts the date stored in XMLDate 
                            //to the format above
                            DateTime XMLDate = (DateTime)x[y];
                            string XMLDatetoString = ""; //Excel Converted Date
                            XMLDatetoString = XMLDate.Year.ToString() +
                                 "-" +
                                 (XMLDate.Month < 10 ? "0" +
                                 XMLDate.Month.ToString() : XMLDate.Month.ToString()) +
                                 "-" +
                                 (XMLDate.Day < 10 ? "0" +
                                 XMLDate.Day.ToString() : XMLDate.Day.ToString()) +
                                 "T" +
                                 (XMLDate.Hour < 10 ? "0" +
                                 XMLDate.Hour.ToString() : XMLDate.Hour.ToString()) +
                                 ":" +
                                 (XMLDate.Minute < 10 ? "0" +
                                 XMLDate.Minute.ToString() : XMLDate.Minute.ToString()) +
                                 ":" +
                                 (XMLDate.Second < 10 ? "0" +
                                 XMLDate.Second.ToString() : XMLDate.Second.ToString()) +
                                 ".000";
                            excelDoc.Write("<Cell ss:StyleID=\"DateLiteral\">" +
                                         "<Data ss:Type=\"DateTime\">");
                            excelDoc.Write(XMLDatetoString);
                            excelDoc.Write("</Data></Cell>");
                            break;
                        case "System.Boolean":
                            excelDoc.Write("<Cell ss:StyleID=\"StringLiteral\">" +
                                        "<Data ss:Type=\"String\">");
                            excelDoc.Write(x[y].ToString());
                            excelDoc.Write("</Data></Cell>");
                            break;
                        case "System.Int16":
                        case "System.Int32":
                        case "System.Int64":
                        case "System.Byte":
                            excelDoc.Write("<Cell ss:StyleID=\"Integer\">" +
                                    "<Data ss:Type=\"Number\">");
                            excelDoc.Write(x[y].ToString());
                            excelDoc.Write("</Data></Cell>");
                            break;
                        case "System.Decimal":
                        case "System.Double":
                            excelDoc.Write("<Cell ss:StyleID=\"Decimal\">" +
                                  "<Data ss:Type=\"Number\">");
                            excelDoc.Write(x[y].ToString());
                            excelDoc.Write("</Data></Cell>");
                            break;
                        case "System.DBNull":
                            excelDoc.Write("<Cell ss:StyleID=\"StringLiteral\">" +
                                  "<Data ss:Type=\"String\">");
                            excelDoc.Write("");
                            excelDoc.Write("</Data></Cell>");
                            break;
                        default:
                            throw (new Exception(rowType.ToString() + " not handled."));
                    }
                }
                excelDoc.Write("</Row>");
            }
            excelDoc.Write("</Table>");
            excelDoc.Write("</Worksheet>");               
            sheetCount++;
        }

        const string endExcelOptions1 = "\r\n<WorksheetOptions xmlns=\"urn:schemas-microsoft-com:office:excel\">\r\n" +
            "<Selected/>\r\n" +
            "<ProtectObjects>False</ProtectObjects>\r\n" +
            "<ProtectScenarios>False</ProtectScenarios>\r\n" +
            "</WorksheetOptions>\r\n";

        excelDoc.Write(endExcelOptions1);
        excelDoc.Write("</Workbook>");
        excelDoc.Close();
    }

File opens but excel gives an error "The file format an extension doesn not match" — user1034912, Commented Jul 16, 2021 at 0:21

Gayan Chinthaka Dharmarathna · Accepted Answer · 2017-04-05 09:00:59Z

If you make data table or datagridview from the code you can save all data using this simple method.this method not recomended but its working 100%, even you are not install MS Excel in your computer.

try
 {
  SaveFileDialog saveFileDialog1 = new SaveFileDialog();
  saveFileDialog1.Filter = "Excel Documents (*.xls)|*.xls";
  saveFileDialog1.FileName = "Employee Details.xls";
  if (saveFileDialog1.ShowDialog() == DialogResult.OK)
  {
  string fname = saveFileDialog1.FileName;
  StreamWriter wr = new StreamWriter(fname);
  for (int i = 0; i <DataTable.Columns.Count; i++)
  {
  wr.Write(DataTable.Columns[i].ToString().ToUpper() + "\t");
  }
  wr.WriteLine();

  //write rows to excel file
  for (int i = 0; i < (DataTable.Rows.Count); i++)
  {
  for (int j = 0; j < DataTable.Columns.Count; j++)
  {
  if (DataTable.Rows[i][j] != null)
  {
  wr.Write(Convert.ToString(getallData.Rows[i][j]) + "\t");
  }
   else
   {
   wr.Write("\t");
   }
   }
   //go to next line
   wr.WriteLine();
   }
   //close file
   wr.Close();
   }
   }
   catch (Exception)
   {
    MessageBox.Show("Error Create Excel Sheet!");
   }

Vladimir Venegas · Accepted Answer · 2017-09-27 15:18:35Z

1

Some time ago, I created a DLL on top of NPOI. It's very simple to use it:

IList<DummyPerson> dummyPeople = new List<DummyPerson>();
//Add data to dummyPeople...
IExportEngine engine = new ExcelExportEngine();
engine.AddData(dummyPeople); 
MemoryStream memory = engine.Export();

You could read more about it on here.

By the way, is 100% open source. Feel free to use, edit and share ;)

answered Sep 27, 2017 at 15:18

community wiki

Vladimir Venegas

Add a comment |

Vijay Dodamani · Accepted Answer · 2018-11-05 07:46:39Z

1

To save xls into xlsx format, we just need to call SaveAs method from Microsoft.Office.Interop.Excel library. This method will take around 16 parameters and one of them is file format as well.

Microsoft document: Here SaveAs Method Arguments

The object we need to pass is like

wb.SaveAs(filename, 51, System.Reflection.Missing.Value,
System.Reflection.Missing.Value, false, false, 1,1, true, 
System.Reflection.Missing.Value, System.Reflection.Missing.Value, System.Reflection.Missing.Value)

Here, 51 is is enumeration value for XLSX

For SaveAs in different file formats you can refer the xlFileFormat

answered Nov 5, 2018 at 7:46

community wiki

Vijay Dodamani

There's an old answer about using Office Interop too.
– Rup
Commented Nov 5, 2018 at 14:45

Add a comment |

2 revs, 2 users 80% · Accepted Answer · 2020-11-15 21:26:59Z

1

I wonder why nobody suggested PowerShell with the free ImportExcel Module; it creates XML-Excel files (xlsx) with ease.

Especially easy when creating Excel-sheets coming from Databases like SQL Server...

edited Nov 15, 2020 at 21:26

community wiki

2 revs, 2 users 80%
Klaus Oberdalhoff

FYI, the XLSX extension has nothing to do with XML. It is simply the modern (Office 2007+) version of the XLS file extension.
– TylerH
Commented Nov 15, 2020 at 21:27
1

@TylerH They are XML based though. XLSX files are .zips of XML files, the same idea as the OpenOffice file formats.
– Rup
Commented Nov 16, 2020 at 9:27
@Rup Yes, the files are a proprietary wrapper around XML data. But that doesn't mean the files are "XML-Excel" files. They are just Excel files.
– TylerH
Commented Nov 16, 2020 at 20:12

Add a comment |

3 revs · Accepted Answer · 2021-10-01 07:18:39Z

In my projects, I use some several .net libraries to extract Excel File (both .xls and .xlsx)

To Export data, I frequently use rdlc.

To modify excel files I use (Sample code when I try to set blank Cell A15):

ClosedXML

        //Closed XML
        var workbook = new XLWorkbook(sUrlFile); // load the existing excel file
        var worksheet = workbook.Worksheets.Worksheet(1);
        worksheet.Cell("A15").SetValue("");
        workbook.Save();

IronXL

       string sUrlFile = "G:\\ReportAmortizedDetail.xls";
        WorkBook workbook = WorkBook.Load(sUrlFile);
        WorkSheet sheet = workbook.WorkSheets.First();
        //Select cells easily in Excel notation and return the calculated value
        sheet["A15"].First().Value = "";
        sheet["A15"].First().FormatString = "";

        workbook.Save();
        workbook.Close();
        workbook = null;

SpireXLS (When I try, the library print additional sheet to give information that we use the trial library

            string sUrlFile = "G:\\ReportAmortizedDetail.xls";
            Workbook workbook = new Workbook();
            workbook.LoadFromFile(sUrlFile);
            //Get the 1st sheet
            Worksheet sheet = workbook.Worksheets[0];
            //Specify the cell range
            CellRange range = sheet.Range["A15"];
            //Find all matched text in the range
            CellRange[] cells = range.FindAllString("hi", false, false);
            //Replace text
            foreach (CellRange cell in range)
            {
                cell.Text = "";
            }
            //Save
            workbook.Save();

Jet Oledb

    //ExcelTool Class
    public static int ExcelUpdateSheets(string path, string sWorksheetName, string sCellLocation, string sValue)
    {
        int iResult = -99;
        String sConnectionString = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + path + ";Extended Properties='Excel 8.0;HDR=NO'";
        OleDbConnection objConn = new OleDbConnection(sConnectionString);
        objConn.Open();
        OleDbCommand objCmdSelect = new OleDbCommand("UPDATE [" + sWorksheetName + "$" + sCellLocation + "] SET F1=" + UtilityClass.ValueSQL(sValue), objConn);
        objCmdSelect.ExecuteNonQuery();
        objConn.Close();

        return iResult;
    }

Usage :

    ExcelTool.ExcelUpdateSheets(sUrlFile, "ReportAmortizedDetail", "A15:A15", "");

Aspose

            var workbook = new Aspose.Cells.Workbook(sUrlFile);
            // access first (default) worksheet
            var sheet = workbook.Worksheets[0];
            // access CellsCollection of first worksheet
            var cells = sheet.Cells;
            // write HelloWorld to cells A1
            cells["A15"].Value = "";
            // save spreadsheet to disc
            workbook.Save(sUrlFile);
            workbook.Dispose();
            workbook = null;

Dariusz Woźniak · Accepted Answer · 2023-10-26 10:29:53Z

Reposting answer from I want to create xlsx (Excel) file from c#:

You may use the NPOI library to create an Excel document. It doesn't require Office installed and doesn't use Interop / COM+. It also supports .NET Core.

using var workbook = new XSSFWorkbook();

var sheet = workbook.CreateSheet("Sheet1");

int rowIndex = 0;

var row = sheet.CreateRow(rowIndex++);
int cellIndex = 0;
row.CreateCell(cellIndex++).SetCellValue("ID");
row.CreateCell(cellIndex++).SetCellValue("Name");

var row = sheet.CreateRow(rowIndex++);
cellIndex = 0;
row.CreateCell(cellIndex++).SetCellValue("1");
row.CreateCell(cellIndex++).SetCellValue("One");

var row = sheet.CreateRow(rowIndex++);
cellIndex = 0;
row.CreateCell(cellIndex++).SetCellValue("2");
row.CreateCell(cellIndex++).SetCellValue("Two");


string path = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location)!;
string xlsxPath = Path.Combine(path, $"vdfgdfg.xlsx");

using var fileStream = new FileStream(xlsxPath, FileMode.Create, FileAccess.Write);
workbook.Write(fileStream);

Links:

NuGet: https://www.nuget.org/packages/NPOI
Quite good intro (HTTP!): http://www.independent-software.com/introduction-to-npoi.html
Getting started: https://github.com/nissl-lab/npoi/wiki/Getting-Started-with-NPOI

Shubham · Accepted Answer · 2019-01-04 05:17:40Z

check this out no need for third party libraries you can simply export datatable data to excel file using this

var dt = "your code for getting data into datatable";
            Response.ClearContent();
            Response.AddHeader("content-disposition", string.Format("attachment;filename={0}.xls", DateTime.Now.ToString("yyyy-MM-dd")));
            Response.ContentType = "application/vnd.ms-excel";
            string tab = "";
            foreach (DataColumn dataColumn in dt.Columns)
            {
                Response.Write(tab + dataColumn.ColumnName);
                tab = "\t";
            }
            Response.Write("\n");
            int i;
            foreach (DataRow dataRow in dt.Rows)
            {
                tab = "";
                for (i = 0; i < dt.Columns.Count; i++)
                {
                    Response.Write(tab + dataRow[i].ToString());
                    tab = "\t";
                }
                Response.Write("\n");
            }
            Response.End();

That generates a tab-separated file and saves it with an .XLS extension so that it gets opened by Excel. It's not a real Excel file, and you can't include formatting etc. There are similar answers here which try the same trick with HTML and the wrong extension. — Rup, Commented Jan 4, 2019 at 9:44

2 revs, 2 users 71% · Accepted Answer · 2015-03-13 21:17:16Z

-5

I am using following code for create excel 2007 file which create the file and write in that file but when i open the file but it give me error that exel cannot open the file bcz file might be coruupted or extension of the file is not compatible. but if i used .xls for file it work fines

for (int i = 0; i < TotalFile; i++)
{
    Contact.Clear();
    if (innerloop == SplitSize)
    {
        for (int j = 0; j < SplitSize; j++)
        {
            string strContact = DSt.Tables[0].Rows[i * SplitSize + j][0].ToString();
            Contact.Add(strContact);
        }
        string strExcel = strFileName + "_" + i.ToString() + ".xlsx";
                         File.WriteAllLines(strExcel, Contact.ToArray());
    }
}

also refer link

http://dotnet-magic.blogspot.in/2011/10/createformat-excel-file-from-cnet.html

edited Mar 13, 2015 at 21:17

community wiki

2 revs, 2 users 71%
saurabh27

2

That all relies on your Contact class, and you haven't told us what that is. If it works for xls then chances are you're actually writing out HTML which isn't a real Excel file. And your link is using interop, which as mentioned above shouldn't be used server-side and can be slow filling large tables.
– Rup
Commented Dec 22, 2014 at 20:48
1

Contact is linkedlist not a class.declare a linkledist and used it because i haven't know the size of data so i used linkedlist.
– saurabh27
Commented Dec 23, 2014 at 9:53
1

Oh, so you're producing a plain text file with one item per line? So Excel is treating it as a CSV without the commas?
– Rup
Commented Dec 23, 2014 at 9:55

Add a comment |

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