[c#] Exporting the values in List to excel

Hi I am having a list container which contains the list of values. I wish to export the list values directly to Excel. Is there any way to do it directly?

I know, I am late to this party, however I think it could be helpful for others.

Already posted answers are for csv and other one is by Interop dll where you need to install excel over the server, every approach has its own pros and cons. Here is an option which will give you

1. Perfect excel output [not csv]
2. With perfect excel and your data type match
3. Without excel installation
4. Pass list and get Excel output :)

you can achieve this by using NPOI DLL, available for both .net as well as for .net core

Steps :

1. Import NPOI DLL
2. Add Section 1 and 2 code provided below
3. Good to go

Section 1

This code performs below task :

1. Creating New Excel object - _workbook = new XSSFWorkbook();
2. Creating New Excel Sheet object - _sheet =_workbook.CreateSheet(_sheetName);
3. Invokes WriteData() - explained later Finally, creating and
4. returning MemoryStream object

=============================================================================

using NPOI.SS.UserModel;
using NPOI.XSSF.UserModel;
using System;
using System.Collections.Generic;
using System.IO;
using System.Net;
using System.Net.Http;
using System.Net.Http.Headers;

namespace GenericExcelExport.ExcelExport
{
    public interface IAbstractDataExport
    {
        HttpResponseMessage Export(List exportData, string fileName, string sheetName);
    }

    public abstract class AbstractDataExport : IAbstractDataExport
    {
        protected string _sheetName;
        protected string _fileName;
        protected List _headers;
        protected List _type;
        protected IWorkbook _workbook;
        protected ISheet _sheet;
        private const string DefaultSheetName = "Sheet1";

        public HttpResponseMessage Export
              (List exportData, string fileName, string sheetName = DefaultSheetName)
        {
            _fileName = fileName;
            _sheetName = sheetName;

            _workbook = new XSSFWorkbook(); //Creating New Excel object
            _sheet = _workbook.CreateSheet(_sheetName); //Creating New Excel Sheet object

            var headerStyle = _workbook.CreateCellStyle(); //Formatting
            var headerFont = _workbook.CreateFont();
            headerFont.IsBold = true;
            headerStyle.SetFont(headerFont);

            WriteData(exportData); //your list object to NPOI excel conversion happens here

            //Header
            var header = _sheet.CreateRow(0);
            for (var i = 0; i < _headers.Count; i++)
            {
                var cell = header.CreateCell(i);
                cell.SetCellValue(_headers[i]);
                cell.CellStyle = headerStyle;
            }

            for (var i = 0; i < _headers.Count; i++)
            {
                _sheet.AutoSizeColumn(i);
            }

            using (var memoryStream = new MemoryStream()) //creating memoryStream
            {
                _workbook.Write(memoryStream);
                var response = new HttpResponseMessage(HttpStatusCode.OK)
                {
                    Content = new ByteArrayContent(memoryStream.ToArray())
                };

                response.Content.Headers.ContentType = new MediaTypeHeaderValue
                       ("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
                response.Content.Headers.ContentDisposition = 
                       new ContentDispositionHeaderValue("attachment")
                {
                    FileName = $"{_fileName}_{DateTime.Now.ToString("yyyyMMddHHmmss")}.xlsx"
                };

                return response;
            }
        }

        //Generic Definition to handle all types of List
        public abstract void WriteData(List exportData);
    }
}

=============================================================================

Section 2

In section 2, we will be performing below steps :

1. Converts List to DataTable Reflection to read property name, your
2. Column header will be coming from here
3. Loop through DataTable to Create excel Rows

=============================================================================

using NPOI.SS.UserModel;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Text.RegularExpressions;

namespace GenericExcelExport.ExcelExport
{
    public class AbstractDataExportBridge : AbstractDataExport
    {
        public AbstractDataExportBridge()
        {
            _headers = new List<string>();
            _type = new List<string>();
        }

        public override void WriteData<T>(List<T> exportData)
        {
            PropertyDescriptorCollection properties = TypeDescriptor.GetProperties(typeof(T));

            DataTable table = new DataTable();

            foreach (PropertyDescriptor prop in properties)
            {
                var type = Nullable.GetUnderlyingType(prop.PropertyType) ?? prop.PropertyType;
                _type.Add(type.Name);
                table.Columns.Add(prop.Name, Nullable.GetUnderlyingType(prop.PropertyType) ?? 
                                  prop.PropertyType);
                string name = Regex.Replace(prop.Name, "([A-Z])", " $1").Trim(); //space separated 
                                                                           //name by caps for header
                _headers.Add(name);
            }

            foreach (T item in exportData)
            {
                DataRow row = table.NewRow();
                foreach (PropertyDescriptor prop in properties)
                    row[prop.Name] = prop.GetValue(item) ?? DBNull.Value;
                table.Rows.Add(row);
            }

            IRow sheetRow = null;

            for (int i = 0; i < table.Rows.Count; i++)
            {
                sheetRow = _sheet.CreateRow(i + 1);
                for (int j = 0; j < table.Columns.Count; j++)
                {
                    ICell Row1 = sheetRow.CreateCell(j);

                    string type = _type[j].ToLower();
                    var currentCellValue = table.Rows[i][j];

                    if (currentCellValue != null && 
                        !string.IsNullOrEmpty(Convert.ToString(currentCellValue)))
                    {
                        if (type == "string")
                        {
                            Row1.SetCellValue(Convert.ToString(currentCellValue));
                        }
                        else if (type == "int32")
                        {
                            Row1.SetCellValue(Convert.ToInt32(currentCellValue));
                        }
                        else if (type == "double")
                        {
                            Row1.SetCellValue(Convert.ToDouble(currentCellValue));
                        }
                    }
                    else
                    {
                        Row1.SetCellValue(string.Empty);
                    }
                }
            }
        }
    }
}

=============================================================================

Now you just need to call WriteData() function by passing your list, and it will provide you your excel.

I have tested it in WEB API and WEB API Core, works like a charm.

List<"classname"> getreport = cs.getcompletionreport(); 

var getreported = getreport.Select(c => new { demographic = c.rName);   

where cs.getcompletionreport() reference class file is Business Layer for App
I hope this helps.

the one easy way to do it is to open Excel create sheet containing test data you want to export then say to excel save as xml open the xml see the xml format excel is expecting and generate it by head replacing the test data with export data

SpreadsheetML Markup Spec

@lan this is xml fo a simle execel file with one column value i genereted with office 2003 this format is for office 2003 and above

<?xml version="1.0"?>
<?mso-application progid="Excel.Sheet"?>
<Workbook xmlns="urn:schemas-microsoft-com:office:spreadsheet"
 xmlns:o="urn:schemas-microsoft-com:office:office"
 xmlns:x="urn:schemas-microsoft-com:office:excel"
 xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet"
 xmlns:html="http://www.w3.org/TR/REC-html40">
 <DocumentProperties xmlns="urn:schemas-microsoft-com:office:office">
  <Author>Dancho</Author>
  <LastAuthor>Dancho</LastAuthor>
  <Created>2010-02-05T10:15:54Z</Created>
  <Company>cc</Company>
  <Version>11.9999</Version>
 </DocumentProperties>
 <ExcelWorkbook xmlns="urn:schemas-microsoft-com:office:excel">
  <WindowHeight>13800</WindowHeight>
  <WindowWidth>24795</WindowWidth>
  <WindowTopX>480</WindowTopX>
  <WindowTopY>105</WindowTopY>
  <ProtectStructure>False</ProtectStructure>
  <ProtectWindows>False</ProtectWindows>
 </ExcelWorkbook>
 <Styles>
  <Style ss:ID="Default" ss:Name="Normal">
   <Alignment ss:Vertical="Bottom"/>
   <Borders/>
   <Font/>
   <Interior/>
   <NumberFormat/>
   <Protection/>
  </Style>
 </Styles>
 <Worksheet ss:Name="Sheet1">
  <Table ss:ExpandedColumnCount="1" ss:ExpandedRowCount="6" x:FullColumns="1"
   x:FullRows="1">
   <Row>
    <Cell><Data ss:Type="String">Value1</Data></Cell>
   </Row>
   <Row>
    <Cell><Data ss:Type="String">Value2</Data></Cell>
   </Row>
   <Row>
    <Cell><Data ss:Type="String">Value3</Data></Cell>
   </Row>
   <Row>
    <Cell><Data ss:Type="String">Value4</Data></Cell>
   </Row>
   <Row>
    <Cell><Data ss:Type="String">Value5</Data></Cell>
   </Row>
   <Row>
    <Cell><Data ss:Type="String">Value6</Data></Cell>
   </Row>
  </Table>
  <WorksheetOptions xmlns="urn:schemas-microsoft-com:office:excel">
   <Selected/>
   <Panes>
    <Pane>
     <Number>3</Number>
     <ActiveRow>5</ActiveRow>
    </Pane>
   </Panes>
   <ProtectObjects>False</ProtectObjects>
   <ProtectScenarios>False</ProtectScenarios>
  </WorksheetOptions>
 </Worksheet>
 <Worksheet ss:Name="Sheet2">
  <WorksheetOptions xmlns="urn:schemas-microsoft-com:office:excel">
   <ProtectObjects>False</ProtectObjects>
   <ProtectScenarios>False</ProtectScenarios>
  </WorksheetOptions>
 </Worksheet>
 <Worksheet ss:Name="Sheet3">
  <WorksheetOptions xmlns="urn:schemas-microsoft-com:office:excel">
   <ProtectObjects>False</ProtectObjects>
   <ProtectScenarios>False</ProtectScenarios>
  </WorksheetOptions>
 </Worksheet>
</Workbook>

Depending on the environment you're wanting to do this in, it is possible by using the Excel Interop. It's quite a mess dealing with COM however and ensuring you clear up resources else Excel instances stay hanging around on your machine.

Checkout this MSDN Example if you want to learn more.

Depending on your format you could produce CSV or SpreadsheetML yourself, thats not too hard. Other alternatives are to use 3rd party libraries to do it. Obviously they cost money though.

The most straightforward way (in my opinion) would be to simply put together a CSV file. If you want to get into formatting and actually writing to a *.xlsx file, there are more complicated solutions (and APIs) to do that for you.

You could output them to a .csv file and open the file in excel. Is that direct enough?

Using ClosedXML library( there is no need to install MS Excel

I just write a simple example to show you how you can name the file, the worksheet and select cells:

    var workbook = new XLWorkbook();
    workbook.AddWorksheet("sheetName");
    var ws = workbook.Worksheet("sheetName");

    int row = 1;
    foreach (object item in itemList)
    {
        ws.Cell("A" + row.ToString()).Value = item.ToString();
        row++;
    }

    workbook.SaveAs("yourExcel.xlsx");

If you prefer you can create a System.Data.DataSet or a System.Data.DataTable with all data and then just add it as a workseet with workbook.AddWorksheet(yourDataset) or workbook.AddWorksheet(yourDataTable);

Fast way - ArrayToExcel (github)

byte[] excel = myList.ToExcel();
File.WriteAllBytes("result.xlsx", excel);

Exporting values List to Excel

1. Install in nuget next reference
2. Install-Package Syncfusion.XlsIO.Net.Core -Version 17.2.0.35
3. Install-Package ClosedXML -Version 0.94.2

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using ClosedXML;
using ClosedXML.Excel;
using Syncfusion.XlsIO;

namespace ExporteExcel
{
    class Program
    {
        public class Auto
        {
            public string Marca { get; set; }

            public string Modelo { get; set; }
            public int Ano { get; set; }

            public string Color { get; set; }
            public int Peronsas { get; set; }
            public int Cilindros { get; set; }
        }
        static void Main(string[] args)
        {
            //Lista Estatica
            List<Auto> Auto = new List<Program.Auto>()
            {
                new Auto{Marca = "Chevrolet", Modelo = "Sport", Ano = 2019, Color= "Azul", Cilindros=6, Peronsas= 4 },
                new Auto{Marca = "Chevrolet", Modelo = "Sport", Ano = 2018, Color= "Azul", Cilindros=6, Peronsas= 4 },
                new Auto{Marca = "Chevrolet", Modelo = "Sport", Ano = 2017, Color= "Azul", Cilindros=6, Peronsas= 4 }
            };
            //Inizializar Librerias
            var workbook = new XLWorkbook();
            workbook.AddWorksheet("sheetName");
            var ws = workbook.Worksheet("sheetName");
            //Recorrer el objecto
            int row = 1;
            foreach (var c in Auto)
            {
                //Escribrie en Excel en cada celda
                ws.Cell("A" + row.ToString()).Value = c.Marca;
                ws.Cell("B" + row.ToString()).Value = c.Modelo;
                ws.Cell("C" + row.ToString()).Value = c.Ano;
                ws.Cell("D" + row.ToString()).Value = c.Color;
                ws.Cell("E" + row.ToString()).Value = c.Cilindros;
                ws.Cell("F" + row.ToString()).Value = c.Peronsas;
                row++;

            }
            //Guardar Excel 
            //Ruta = Nombre_Proyecto\bin\Debug
            workbook.SaveAs("Coches.xlsx");
        }
    }
}

Using the CSV idea, if it's just a list of Strings. Assuming l is your list:

using System.IO;

using(StreamWriter sw = File.CreateText("list.csv"))
{
  for(int i = 0; i < l.Count; i++)
  {
    sw.WriteLine(l[i]);
  }
}

The simplest way using ClosedXml.

Imports ClosedXML.Excel

var dataList = new List<string>() { "a", "b", "c" };
var workbook = new XLWorkbook();     //creates the workbook
var wsDetailedData = workbook.AddWorksheet("data"); //creates the worksheet with sheetname 'data'
wsDetailedData.Cell(1, 1).InsertTable(dataList); //inserts the data to cell A1 including default column name
workbook.SaveAs(@"C:\data.xlsx"); //saves the workbook

For more info, you can also check wiki of ClosedXml. https://github.com/closedxml/closedxml/wiki