How to create, read and edit excel files in asp.net core

Hi Naresh,

Use Open XML

To read data from excel 

https://www.c-sharpcorner.com/article/how-to-read-data-from-an-excel-sheet/

To add and update 

https://www.c-sharpcorner.com/blogs/add-update-rows-data-in-excel-using-open-xml-and-c-sharp

string filename = FileUpload1.FileName;
string extension = Path.GetExtension(FileUpload1.PostedFile.FileName);

String PATH = Server.MapPath("~/NewFolder1/") + filename;
FileUpload1.SaveAs(PATH);
FileStream stream = File.Open(PATH, FileMode.Open, FileAccess.Read);
string filename_tmp = ""; // 9aug21
IExcelDataReader excelReader = null;
switch (extension)
{
    case ".xls":
        //1. Reading from a binary Excel file ('97-2003 format; *.xls)
        excelReader = ExcelReaderFactory.CreateBinaryReader(stream);
        filename_tmp = filename.Replace(".xls", ""); // 9aug21
        break;
    case ".xlsx":
        //2. Reading from a OpenXml Excel file (2007 format; *.xlsx)
        excelReader = ExcelReaderFactory.CreateOpenXmlReader(stream);
        filename_tmp = filename.Replace(".xlsx", ""); // 9aug21
        break;
}
excelReader.IsFirstRowAsColumnNames = true;
DataTable dt = new DataTable();
DataSet result = excelReader.AsDataSet();
dt = result.Tables[0];

use iexcel as it is easy to use and free 

Free Spire.XLS for .NET (https://www.e-iceblue.com/Introduce/free-xls-component.html) is capable of creating, reading and editing excel files in asp.net core, and it is free for both personal and commercial use.

You can find its detailed functionalities by visiting the documentation below:

https://www.e-iceblue.com/Tutorials/Spire.XLS/Spire.XLS-Program-Guide/Spire.XLS-Program-Guide-Content.html