c# - Read CSV to list of objects

Question

(This question already has answers here): question from:https://stackoverflow.com/questions/26790477/read-csv-to-list-of-objects

Answer 1

Why not just parse these explicitly? You have a limited number of properties, so it's not very difficult. Instead of using a constructor requiring many arguments, I used a static method that returns a new DailyValues instance as it's return type. This is similar to DateTime.FromBinary etc.

using System;
using System.Collections.Generic;
using System.Linq;
using System.IO;

namespace CsvDemo
{
    class Program
    {
        static void Main(string[] args)
        {
            List<DailyValues> values = File.ReadAllLines("C:\Users\Josh\Sample.csv")
                                           .Skip(1)
                                           .Select(v => DailyValues.FromCsv(v))
                                           .ToList();
        }
    }

    class DailyValues
    {
        DateTime Date;
        decimal Open;
        decimal High;
        decimal Low;
        decimal Close;
        decimal Volume;
        decimal AdjClose;

        public static DailyValues FromCsv(string csvLine)
        {
            string[] values = csvLine.Split(',');
            DailyValues dailyValues = new DailyValues();
            dailyValues.Date = Convert.ToDateTime(values[0]);
            dailyValues.Open = Convert.ToDecimal(values[1]);
            dailyValues.High = Convert.ToDecimal(values[2]);
            dailyValues.Low = Convert.ToDecimal(values[3]);
            dailyValues.Close = Convert.ToDecimal(values[4]);
            dailyValues.Volume = Convert.ToDecimal(values[5]);
            dailyValues.AdjClose = Convert.ToDecimal(values[6]);
            return dailyValues;
        }
    }
}

Of course, you can still add a default constructor, and you will want to add exception handling in case the parsing fails (you can also use TryParse for that).

• The File.ReadAllLines reads all lines from the CSV file into a string array.
• The .Skip(1) skips the header line.
• The .Select(v => DailyValues.FromCsv(v)) uses Linq to select each line and create a new DailyValues instance using the FromCsv method. This creates a System.Collections.Generic.IEnumerable<CsvDemo.DailyValues> type.
• Finally, the .ToList() convers the IEnumerable to a List to match the type you want.

Instead of using Linq you could have simply used a foreach loop to add each DailyValues instance to your list.