C#控制台应用程序（文件管理）

写入程序

using System;
using System.IO;
using System.Linq;
using System.Text;
namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            string file = @"E:\mydir\f2.dat";
            string path = Path.GetDirectoryName(file);//获取目录
            if (!Directory.Exists(path)) Directory.CreateDirectory(path);//目录不存在创建
            Random r = new Random();
            int num = r.Next(6, 11);//随机生成的成绩数6~10之间
            double[] scores = new double[num];
            for (int i = 0; i < num; i++)
            {
                scores[i] = Math.Round(r.NextDouble() * 100, 1);//保留1位小数
            }
            string s = String.Join(",", scores);//写入文件的数据，以逗号分隔
            FileStream fs = new FileStream(file, FileMode.OpenOrCreate, FileAccess.Write);
            StreamWriter sw = new StreamWriter(fs);
            sw.Write(s);
            sw.Close();
            fs.Close();
        }
    }
}

读取程序

using System;
using System.IO;
using System.Linq;
using System.Text;
namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            string file = @"E:\mydir\f2.dat";


            FileStream fs = new FileStream(file,FileMode.Open, FileAccess.Read);
            StreamReader sr = new StreamReader(fs);
            string s = sr.ReadToEnd();
            sr.Close();
            fs.Close();

            double[] scores = s.Split(',').Select(i => double.Parse(i)).ToArray();


            Console.WriteLine(scores[1]);


            Console.ReadKey();
        }
    }
}