C#——文件處理和字符串處理DEMO

問題描述

已有Racer類和冠軍車手數據。

已有程序，把所有的車手信息寫入一個個文件中。

請編寫程序，讀入這些文件，記錄年份和當年冠軍車手姓名，存入SortedDictionary<int, string>（該類與Dictionary用法類似，但會按鍵進行排序；Dictionary用法在4月10日講過），按年代先後順序輸出。

提示：用好string類的IndexOf, Split, SubString等方法，提取信息

保存車手信息的程序如下：

            IList<Racer> racers = Racer.GetChampions();
            for (int i = 0; i < racers.Count; i++)
            {
                Racer r = racers[i];
                FileStream fs = File.Create($"D:/Racer - {r:N}.txt");
                StreamWriter sw = new StreamWriter(fs);
                sw.WriteLine($"{r:A}");
                sw.Write("Cars: ");
                for (int j = 0; j < r.Cars.Length; j++)
                {
                    sw.Write(r.Cars[j] + "\t");
                }
                sw.WriteLine();
                sw.Write("Years: ");
                for (int k = 0; k < r.Years.Length; k++)
                {
                    sw.Write(r.Years[k] + "\t");
                }
                sw.Close();
            }

解決方案

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Homework9
{
    public class Racer : IComparable<Racer>, IFormattable
    {
        public Racer(string firstName = null, string lastName = null, string country = null, int starts = 0, int wins = 0, IEnumerable<int> years = null, IEnumerable<string> cars = null)
        {
            this.FirstName = firstName;
            this.LastName = lastName;
            this.Country = country;
            this.Starts = starts;
            this.Wins = wins;


            var yearsList = new List<int>();
            foreach (var year in years)
            {
                yearsList.Add(year);
            }
            this.Years = yearsList.ToArray();
            var carList = new List<string>();
            foreach (var car in cars)
            {
                carList.Add(car);
            }
            this.Cars = carList.ToArray();


        }
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public string Country { get; set; }
        public int Wins { get; set; }//奪冠場數
        public int Starts { get; set; }//首發場數
        public string[] Cars { get; private set; }//賽車手獲得冠軍那一年使用的所有車型
        public int[] Years { get; private set; }//賽車手獲得冠軍的年份

        public override string ToString()
        {
            return String.Format("{0} {1}", FirstName, LastName);
        }

        public int CompareTo(Racer other)
        {
            if (other == null) throw new ArgumentNullException("other");

            return this.LastName.CompareTo(other.LastName);
        }

        public string ToString(string format)
        {
            return ToString(format, null);
        }

        public string ToString(string format,
              IFormatProvider formatProvider)
        {
            switch (format)
            {
                case null:
                case "N":
                    return ToString();
                case "F":
                    return FirstName;
                case "L":
                    return LastName;
                case "C":
                    return Country;
                case "S":
                    return Starts.ToString();
                case "W":
                    return Wins.ToString();
                case "A":
                    return String.Format("{0} {1}, {2}; starts: {3}, wins: {4}",
                          FirstName, LastName, Country, Starts, Wins);
                default:
                    throw new FormatException(String.Format("Format {0} not supported", format));
            }
        }

        public static IList<Racer> GetChampions()//1950-2008年一級方程式錦標賽冠軍
        {
            IList<Racer> racers = new List<Racer>(40);
            racers.Add(new Racer("Nino", "Farina", "Italy", 33, 5, new int[] { 1950 }, new string[] { "Alfa Romeo" }));
            racers.Add(new Racer("Alberto", "Ascari", "Italy", 32, 10, new int[] { 1952, 1953 }, new string[] { "Ferrari" }));
            racers.Add(new Racer("Juan Manuel", "Fangio", "Argentina", 51, 24, new int[] { 1951, 1954, 1955, 1956, 1957 }, new string[] { "Alfa Romeo", "Maserati", "Mercedes", "Ferrari" }));
            racers.Add(new Racer("Mike", "Hawthorn", "UK", 45, 3, new int[] { 1958 }, new string[] { "Ferrari" }));
            racers.Add(new Racer("Phil", "Hill", "USA", 48, 3, new int[] { 1961 }, new string[] { "Ferrari" }));
            racers.Add(new Racer("John", "Surtees", "UK", 111, 6, new int[] { 1964 }, new string[] { "Ferrari" }));
            racers.Add(new Racer("Jim", "Clark", "UK", 72, 25, new int[] { 1963, 1965 }, new string[] { "Lotus" }));
            racers.Add(new Racer("Jack", "Brabham", "Australia", 125, 14, new int[] { 1959, 1960, 1966 }, new string[] { "Cooper", "Brabham" }));
            racers.Add(new Racer("Denny", "Hulme", "New Zealand", 112, 8, new int[] { 1967 }, new string[] { "Brabham" }));
            racers.Add(new Racer("Graham", "Hill", "UK", 176, 14, new int[] { 1962, 1968 }, new string[] { "BRM", "Lotus" }));
            racers.Add(new Racer("Jochen", "Rindt", "Austria", 60, 6, new int[] { 1970 }, new string[] { "Lotus" }));
            racers.Add(new Racer("Jackie", "Stewart", "UK", 99, 27, new int[] { 1969, 1971, 1973 }, new string[] { "Matra", "Tyrrell" }));
            racers.Add(new Racer("Emerson", "Fittipaldi", "Brazil", 143, 14, new int[] { 1972, 1974 }, new string[] { "Lotus", "McLaren" }));
            racers.Add(new Racer("James", "Hunt", "UK", 91, 10, new int[] { 1976 }, new string[] { "McLaren" }));
            racers.Add(new Racer("Mario", "Andretti", "USA", 128, 12, new int[] { 1978 }, new string[] { "Lotus" }));
            racers.Add(new Racer("Jody", "Scheckter", "South Africa", 112, 10, new int[] { 1979 }, new string[] { "Ferrari" }));
            racers.Add(new Racer("Alan", "Jones", "Australia", 115, 12, new int[] { 1980 }, new string[] { "Williams" }));
            racers.Add(new Racer("Keke", "Rosberg", "Finland", 114, 5, new int[] { 1982 }, new string[] { "Williams" }));
            racers.Add(new Racer("Niki", "Lauda", "Austria", 173, 25, new int[] { 1975, 1977, 1984 }, new string[] { "Ferrari", "McLaren" }));
            racers.Add(new Racer("Nelson", "Piquet", "Brazil", 204, 23, new int[] { 1981, 1983, 1987 }, new string[] { "Brabham", "Williams" }));
            racers.Add(new Racer("Ayrton", "Senna", "Brazil", 161, 41, new int[] { 1988, 1990, 1991 }, new string[] { "McLaren" }));
            racers.Add(new Racer("Nigel", "Mansell", "UK", 187, 31, new int[] { 1992 }, new string[] { "Williams" }));
            racers.Add(new Racer("Alain", "Prost", "France", 197, 51, new int[] { 1985, 1986, 1989, 1993 }, new string[] { "McLaren", "Williams" }));
            racers.Add(new Racer("Damon", "Hill", "UK", 114, 22, new int[] { 1996 }, new string[] { "Williams" }));
            racers.Add(new Racer("Jacques", "Villeneuve", "Canada", 165, 11, new int[] { 1997 }, new string[] { "Williams" }));
            racers.Add(new Racer("Mika", "Hakkinen", "Finland", 160, 20, new int[] { 1998, 1999 }, new string[] { "McLaren" }));
            racers.Add(new Racer("Michael", "Schumacher", "Germany", 250, 91, new int[] { 1994, 1995, 2000, 2001, 2002, 2003, 2004 }, new string[] { "Benetton", "Ferrari" }));
            racers.Add(new Racer("Fernando", "Alonso", "Spain", 132, 21, new int[] { 2005, 2006 }, new string[] { "Renault" }));
            racers.Add(new Racer("Kimi", "Rikknen", "Finland", 148, 17, new int[] { 2007 }, new string[] { "Ferrari" }));
            racers.Add(new Racer("Lewis", "Hamilton", "UK", 44, 9, new int[] { 2008 }, new string[] { "McLaren" }));

            return racers;
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            IList<Racer> racers = Racer.GetChampions();
            for (int i = 0; i < racers.Count; i++)
            {
                Racer r = racers[i];
                FileStream fs = File.Create($"out/Racer - {r:N}.txt");
                StreamWriter sw = new StreamWriter(fs);
                sw.WriteLine($"{r:A}");
                sw.Write("Cars: ");
                for (int j = 0; j < r.Cars.Length; j++)
                {
                    sw.Write(r.Cars[j] + "\t");
                }
                sw.WriteLine();
                sw.Write("Years: ");
                for (int k = 0; k < r.Years.Length; k++)
                {
                    sw.Write(r.Years[k] + "\t");
                }
                sw.Close();
            }
            SortedDictionary<int, string> sd = new SortedDictionary<int, string>();
            for (int i = 0; i < racers.Count; i++)
            {
                Racer r = racers[i];
                FileStream fs = File.Open($"out/Racer - {r:N}.txt",FileMode.Open);
                StreamReader sr = new StreamReader(fs);
                string s=sr.ReadToEnd();
                Console.WriteLine(s);
                string name = s.Substring(0, s.IndexOf(","));
                Console.WriteLine(name);
                string[] years = s.Substring(s.IndexOf("Years: ") + 7).Split('\t');
                Console.WriteLine(years);
                foreach(string year in years){
                    Console.WriteLine(year);
                    if(year!="")
                        sd.Add(int.Parse(year),name);
                }
            }
            foreach (KeyValuePair<int, string> pair in sd)
            {
                Console.WriteLine(pair.Key + ":" + pair.Value);
            }
        }
    }
}

運行結果

參考文章