c# - 如何进行统计；第二：如何写这样的文件

Question

首先：我必须按省从我的csv（https://pastebin.com/jxNSzVYP）中进行统计。在某个地方你可以找到像“HU-GD”这样的省份，然后你必须看到像“HU”这样的前2个字母。我必须计算那里有多少个 SI/GA/etc 省。之后，我必须写出，当它至少是 3 时。（如果 csv 发生变化，我的意思是不会再有 HU/SI/ 等，并且会有一个新的，程序必须计算它。）[检查: 描述预期结果]

第二：我必须制作一个新的“newCNtunnels.csv”文件。当有一个像“HU-GD”这样的省份时，我必须将它们分开并用相同的数据写入它们，只是省份不同。[检查：描述预期结果]

我不是一个大程序员，所以请不要过度复杂化。对不起我的英语不好。这不是我的第一语言，但可能你已经注意到了。谢谢您的帮助！

我正在使用 Windows 10 和 Visual Studio。C#语言

    struct datas
    {
        public string name;
        public int length;
        public string date;
        public string province;
    }
    datas[] tunnel = new datas[99];


        int i = 0;
        int howmanyrow= 0;

        StreamReader sr = new StreamReader("CNtunnels.csv");
        sr.ReadLine();
        while (!sr.EndOfStream)
        {
            String[] onerow= sr.ReadLine().Split(';');
            tunnel[i].name= onerow[0];
            tunnel[i].length= Convert.ToInt32(onerow[1]);
            tunnel[i].date= onerow[2];
            tunnel[i].province= onerow[3];
            i++;
            howmanyrow++;

        }
        sr.Close();

异常结果：

https://pastebin.com/EsQz16A0

标签： c#

Answer 1

请参阅以下解决方案：

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

namespace ConsoleApplication1
{
    class Program
    {
        const string INPUT_CSV_FILENAME = @"c:\temp\test.csv";
        const string OUTPUT_CSV_FILENAME = @"c:\temp\test1.csv";
        const string OUTPUT_STATISTICS_FILENAME = @"c:\temp\statistic.txt";
        static void Main(string[] args)
        {
            Data data = new Data(INPUT_CSV_FILENAME);
            data.WriteStatistics(OUTPUT_STATISTICS_FILENAME);
            data.WriteCSV(OUTPUT_CSV_FILENAME);
        }
    }
    class Data
    {
        public static List<Data> datas = new List<Data>();
        public string name;
        public int length;
        public string date;
        public string province;

        public Data() { }
        public Data(string filename)
        {
            StreamReader reader = new StreamReader(filename);
            string line = "";
            int rowCount = 0;

            while ((line = reader.ReadLine()) != null)
            {
                line = line.Trim();
                if (line.Length > 0)
                {
                    string[] splitArray = line.Split(new char[] { ';' });
                    if (++rowCount > 1)
                    {
                        string[] splitProvidence = splitArray[3].Split(new char[] { '-' });

                        foreach (string providence in splitProvidence)
                        {
                            Data newRow = new Data();
                            Data.datas.Add(newRow);

                            newRow.name = splitArray[0];
                            newRow.length = int.Parse(splitArray[1]);
                            newRow.date = splitArray[2];
                            newRow.province = providence;
                        }
                    }

                }
            }
        }
        public void WriteStatistics(string filename)
        {
            StreamWriter writer = new StreamWriter(filename);

            var groups = datas.GroupBy(x => x.province).OrderByDescending(x => x.Count()).ToList();

            foreach (var group in groups)
            {
                writer.WriteLine("{0} - {1}", group.Key, group.Count());
            }
            writer.Flush();
            writer.Close();
        }
        public void WriteCSV(string filename)
        {
            StreamWriter writer = new StreamWriter(filename);
            string header = string.Join(";", new string[] { "name","length","date","province"});
            writer.WriteLine(header);
            foreach (Data data in datas)
            {
                writer.WriteLine(string.Join(";",new string[] {
                    data.name,
                    data.length.ToString(),
                    data.date,
                    data.province
                }));
            }
            writer.Flush();
            writer.Close();
        }
    }
}