Question

我是C＃的新手。我已编写代码从本地计算机上的文档中打开CSV文件。它运行良好，数据解析工作。麻烦的是当我更改代码以从互联网站点打开文件时，我无法让它工作。我可以使用VBA打开这个文件，但我现在想使用C＃ADO.NET。我无法通过Google搜索找到答案。任何人都可以帮助代码和/或指向一个有良好教程的网站。所有人都非常感谢。附上代码，我确定问题出在第24 - 26行;

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

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            //
            // Read in a file line-by-line, and store it all in a List.
            //
            int i = 0;
            DateTime dte;
            List<string> list = new List<string>();
            float[] Prices = new float[4];

            WebClient wc = new WebClient();

            byte[] data = wc.DownloadData("http://www.datasource.com/apps/qt/csv/pricehistory.ac?section=yearly_price_download&code=XXX");

            using (StreamReader reader = new StreamReader(wc))
            {
                string line;
                while ((line = reader.ReadLine()) != null)
                {
                    //list.Add(line); // Add to list.
                    Console.WriteLine(line); // Write to console.

                    string[] parts = line.Split(',');
                    int DateSetter = 1;
                    int DateDone = 0;
                    int CountFloat = 0;
                    int PricesDone = 0;
                    Double Volume = 0;

                    foreach (string part in parts)
                    {
                        Console.WriteLine("{0} : {1}", i, part);

                        if (DateSetter == 1)
                        {
                            dte = DateTime.Parse(part);
                            DateSetter = 2;
                            Console.WriteLine(dte);
                        }
                        if (DateDone == 1)
                        {
                            if (DateSetter < 6)
                            {
                                Prices[CountFloat] = float.Parse(part);
                                CountFloat++;
                                DateSetter++;
                                Console.WriteLine(Prices[3]);
                            } 
                        }
                        DateDone = 1;
                        if (PricesDone == 1)
                        {
                            Volume = double.Parse(part);
                            Console.WriteLine(Volume);
                        }
                        if (DateSetter == 6)
                        {
                            PricesDone = 1;
                        }
                    }

                }
           }
            Console.ReadLine();
        }
    }
}

Answer 1

您粘贴的代码无法编译。但是，您可以使用WebClient下载到字符串，然后将字符串拆分为行：

string content;
using(WebClient wc = new WebClient())
content = wc.DownloadString("http://www.datasource.com/apps/qt/csv/pricehistory.ac?section=yearly_price_download&code=XXX");

foreach(var line in content.Split(new string [] {Environment.NewLine}, StringSplitOptions.None))
{
    //...
}

Answer 2

另一种选择是在你正在做的时候下载数据，然后用MemoryStream包裹它：

WebClient wc = new WebClient();
byte[] data = wc.DownloadData(
    "http://www.datasource.com/apps/qt/csv/pricehistory.ac?section=yearly_price_download&code=XXX");

using (var ms = new MemoryStream(data))
{
    using (var reader = new StreamReader(ms))
    {
        string line;
        while ((line = reader.ReadLine()) != null)
        {
            // do whatever
        }
    }
}

这比分割字符串的优点是它使用的内存要少得多。

无法使用C＃从Internet打开CSV文件

2 个答案: