using System;

using ExcelDataReader;

using System.Collections.Generic;

using System.Data;

using System.IO;

using System.Linq;

using System.Net;

using Newtonsoft.Json;

​

public class Program

{

    public static void Main()

    {

        using (var client = new WebClient())

            {

                var file= client.DownloadData("https://devhow.net/wp-content/uploads/2018/11/SampleExcelData.xlsx");

                var excelContent= ParseExcel(new MemoryStream(file));

                string json= JsonConvert.SerializeObject(excelContent);

                Console.Write(json);

​

            }

    }

     public static IEnumerable<Dictionary<string, object>> ParseExcel(Stream document)

        {

            using (var reader = ExcelReaderFactory.CreateReader(document))

            {

                var result = reader.AsDataSet(new ExcelDataSetConfiguration()

                {

                    UseColumnDataType = true,

                    ConfigureDataTable = (tableReader) => new ExcelDataTableConfiguration()

                    {

                        UseHeaderRow = true,

                    }

                });

                return MapDatasetData(result.Tables.Cast<DataTable>().First());

            }

        }

     public static IEnumerable<Dictionary<string, object>> MapDatasetData(DataTable dt)

        {

            foreach (DataRow dr in dt.Rows)

            {

                var row = new Dictionary<string, object>();

                foreach (DataColumn col in dt.Columns)

                {

                    row.Add(col.ColumnName, dr[col]);

                }

                yield return row;

            }

        }

}