Read Excel in C#

ExcelOperations.cs

public class ExcelOperations
    {

        public List<List<string>> Read(string filePath)
        {

            OleDbConnection conn = new OleDbConnection("Provider = Microsoft.ACE.OLEDB.12.0; Data Source = " + filePath + "; Extended Properties = 'Excel 8.0; HDR=NO'");
            OleDbCommand cmd = new OleDbCommand("select * from [Sheet1$]", conn);
            conn.Open();
            OleDbDataReader dr = cmd.ExecuteReader();

            List<List<string>> data = new List<List<string>>();
            while (dr.Read())
            {
                var obj = dr.GetValue(0);
                if (obj == DBNull.Value) continue;

                var shortList = new List<string>();

                for (int i = 0; i < dr.FieldCount; i++)
                {
                    shortList.Add(dr[i].ToString());
                }

                data.Add(shortList);
            }
            conn.Close();

            return data;
        }

    }