Reading data from excel in to Json object in c#

Connect to the Excel sheet via the ADO.NET OleDb provider. Then, use a JSON library for C# to generate the JSON string, and save the file. (Or use the JavascriptSerialzer, as @boades suggested).

This example uses the JSON.NET library.

using System;
using System.Linq;
using System.Data.OleDb;
using System.Data.Common;
using Newtonsoft.Json;
using System.IO;

namespace ConsoleApplication1 {
    class Program {
        static void Main(string[] args) {
            var pathToExcel = @"C:\path\to\excel\file.xlsx";
            var sheetName = "NameOfSheet";
            var destinationPath = @"C:\path\to\save\json\file.json";

            //Use this connection string if you have Office 2007+ drivers installed and 
            //your data is saved in a .xlsx file
            var connectionString = $@"
                Provider=Microsoft.ACE.OLEDB.12.0;
                Data Source={pathToExcel};
                Extended Properties=""Excel 12.0 Xml;HDR=YES""
            ";

            //Creating and opening a data connection to the Excel sheet 
            using (var conn=new OleDbConnection(connectionString)) {
                conn.Open();

                var cmd=conn.CreateCommand();
                cmd.CommandText = $"SELECT * FROM [{sheetName}$]";

                using (var rdr=cmd.ExecuteReader()) {

                    //LINQ query - when executed will create anonymous objects for each row
                    var query = rdr.Cast<DbDataRecord>().Select(row => new {
                        name = row[0],
                        regno = row[1],
                        description = row[2]
                    });

                    //Generates JSON from the LINQ query
                    var json = JsonConvert.SerializeObject(query);

                    //Write the file to the destination path    
                    File.WriteAllText(destinationPath, json);
                }
            }
        }
    }
}

Links:

• Retrieving and Modifying Data in ADO.NET - how to use connections, commands and readers
• Excel 2007 connection strings
• Older Excel connection strings under the 'OLEDB Providers' section
• JSON libraries for C# can be found on the JSON page
• JSON.NET
• Microsoft Access Database Engine 2010 Redistributable, if you don't have Excel 2007+ installed

Save it as a CSV. Then use File.ReadLines to enumerate over each line, followed by String.Split to read each column. Format the data as a JSON string and save it to a file.

You can give a try to http://exceldatareader.codeplex.com/ library. You must read data from excel to some object, and than convert it to json using JavaScriptSerializer

public class MyRow
{
   public string Cell1;
   public string Cell2;
   public string Cell3;
}

class Program
{
        static void Main()
        {
            var list = new List<MyRow>();
            FileStream stream = File.Open(filePath, FileMode.Open, FileAccess.Read);

            //1. Reading from a binary Excel file ('97-2003 format; *.xls)
            IExcelDataReader excelReader = ExcelReaderFactory.CreateBinaryReader(stream);
            //...
            //2. Reading from a OpenXml Excel file (2007 format; *.xlsx)
            IExcelDataReader excelReader = ExcelReaderFactory.CreateOpenXmlReader(stream);


            //5. Data Reader methods
            while (excelReader.Read())
            {
                   var obj = new MyRow 
                   {
                       Cell1 = excelReader.GetString(0),
                       Cell2 = excelReader.GetString(1),
                       Cell3 = excelReader.GetString(2),
                   }

                   list.Add(obj);
            }

            //6. Free resources (IExcelDataReader is IDisposable)
            excelReader.Close();
            var json = new JavaScriptSerializer().Serialize(list);
            Console.WriteLine(json);
        }
    }